Patent Description:
<NUM>,<NUM>-pentanediol is a colorless or pale yellow liquid, has two hydroxyl groups (-OH) and an alkyl group having five carbon atoms, and is characterized in that it is miscible both with water and with oil-type solutions. Due to these properties, <NUM>,<NUM>-pentanediol is used as a moisturizer, which is an active ingredient that prevents skin from becoming dry due to environmental conditions and weather in the cosmetic field, and is used for baby products, bath products, makeup products, cleansing products, skin care products, and hair care products.

Moreover, <NUM>,<NUM>-pentanediol has antibacterial activity, so when used together with other preservatives, it is capable of playing a role of increasing the antibacterial activity, and thus may be used as an alternative to existing preservatives.

In general, <NUM>,<NUM>-pentanediol is prepared from n-pent-<NUM>-ene, obtained from petrochemicals, using peroxides. Here, the diester of <NUM>,<NUM>-pentanediol formed as an intermediate has to be removed, which generates a large amount of wastewater. In addition, since n-pent-<NUM>-ene has a very low boiling point, it is difficult to handle, so it is desirable to find a simple synthesis route that is feasible on an industrial scale.

As an alternative thereto, it is possible to synthesize <NUM>,<NUM>-pentanediol using furfural or furfuryl alcohol, which is a material capable of being obtained from renewable materials, as a reactant, and since furfural or the like may be obtained in large amounts from grain waste containing sugar, research thereto is ongoing in view of the use of waste and environmental protection.

As shown in <FIG>, in literature it has been reported that various compounds are formed through the hydrogenation or hydrogenolysis of furfural or furfuryl alcohol.

In Non-Patent Document <NUM> [<NPL>)], it has been reported that a mixture of furfuryl alcohol, <NUM>-pentanol, tetrahydrofurfuryl alcohol, <NUM>,<NUM>-pentanediol and <NUM>,<NUM>-pentanediol is obtained through hydrogenolysis/hydrogenation of furfural in the presence of platinum black at room temperature.

Additionally, in Non-Patent Document <NUM> [<NPL>)], it has been reported that <NUM>% of <NUM>,<NUM>-pentanediol and <NUM>% of <NUM>,<NUM>-pentanediol are obtained by reacting liquid furfuryl alcohol with hydrogen at <NUM> using copper chromite as a catalyst.

Research is ongoing into methods capable of increasing the reaction yield of <NUM>,<NUM>-pentanediol, the use of which has increased in cosmetics, among mixtures generated through the hydrogenation reaction of furfural or furfuryl alcohol. <CIT>) discloses a method of preparing <NUM>,<NUM>-pentanediol from furfuryl alcohol using an alkaline compound composed of an alkali metal or alkaline earth metal compound in the presence of a copper-containing metal catalyst, but the reaction yield of <NUM>,<NUM>-pentanediol thus prepared is reported to be less than <NUM>% (Patent Document <NUM>).

In addition, <CIT>) discloses a method of synthesizing <NUM>,<NUM>-pentanediol from furfural or furfuryl alcohol using a catalyst in which at least one metal compound selected from among platinum, rhodium, ruthenium, nickel, and palladium is supported on a support, and the maximum yield of <NUM>,<NUM>-pentanediol is reported to be <NUM>% using, for example, a platinum oxide catalyst (Patent Document <NUM>).

As described above, since the method of preparing <NUM>,<NUM>-pentanediol through the hydrogenation reaction of furfural or furfuryl alcohol is regarded as an important technology capable of utilizing biomass, various catalysts therefor are being developed. Research and development on a novel catalyst having higher reaction selectivity for <NUM>,<NUM>-pentanediol and a method of preparing <NUM>,<NUM>-pentanediol using the same are continuously required.

The reactions described above may be carried out in a gas phase or a liquid phase, and a liquid-phase reaction is more advantageous than a gas-phase reaction in view of controlling the reaction temperature, whereas the gas-phase reaction is more advantageous in view of productivity.

The present disclosure is intended to develop a gas-phase reaction or liquid-phase reaction method capable of preparing <NUM>,<NUM>-pentanediol from furfuryl alcohol and/or furfural in an efficient and environmentally friendly manner, and an efficient catalyst therefor.

The inventors of the present disclosure ascertained that the reaction selectivity of <NUM>,<NUM>-pentanediol may be increased when using a catalyst system of a specific metal combination, among surveyed catalyst systems, to prepare <NUM>,<NUM>-pentanediol at a high yield compared to existing catalyst systems, thus culminating in the present disclosure. <NPL> reports about the development of a hybrid conversion process for the selective hydrogenation of butyric acid combined with fermentation of glucose. Bimetallic ruthenium-tin catalysts supported on zinc oxide (Ru-Sn/ZnO) show good performance in the vapor-phase hydrogenation of biomass-derived butyric acid to n-butanol, as well as good long-term performance. <NPL> discloses the production of <NUM>,<NUM>-Dimethylfuran in <NUM>% overall yield from fructose in <NUM>-butanol through a combination of dehydration over Amberlyst-<NUM> and hydrogenolysis over the Ru-Sn/ZnO catalyst. <CIT> relates to a process for the preparation of <NUM>,<NUM>-pentanediol by reaction of a starting material comprising one or both compounds from the group consisting of furfuryl alcohol and furfural with hydrogen in the presence of a heterogeneous catalyst and discloses (ex. <NUM>) a Ru-Sn on alumina catalyst, which has no apparent activity towards the formation of pentanediol.

The present disclosure has been made keeping in mind the problems encountered in the related art, and an objective of the present disclosure is to provide a method for a gas-phase or liquid-phase reaction with high reaction selectivity for <NUM>,<NUM>-pentanediol in the hydrogenation reaction of furfural or furfuryl alcohol, and a method of preparing <NUM>,<NUM>-pentanediol.

In order to accomplish the above objective, the present disclosure provides a method of preparing <NUM>,<NUM>-pentanediol according to claim <NUM>.

According to the present disclosure, <NUM>,<NUM>-pentanediol can be produced at a high yield through a gas-phase reaction or a liquid-phase reaction of hydrogen and a starting material including at least one of furfural and furfuryl alcohol using a catalyst system formed by supporting a catalytically active metal including at least one transition metal and tin (Sn) on a basic support.

Unless otherwise defined, all technical and scientific terms used herein have the same meanings as those typically understood by those skilled in the art to which the present disclosure belongs. Generally, the nomenclature used herein is well known in the art and is typical.

As used herein, when any part is said to "comprise" or "include" any element, this does not mean that other elements are excluded, and such other elements may be further included unless otherwise specifically mentioned.

The catalyst used to prepare <NUM>,<NUM>-pentanediol through the reaction of hydrogen with a starting material including at least one of furfural and furfuryl alcohol according to the present disclosure is configured such that an active metal including at least one transition metal and tin (Sn) is supported on a basic support.

The starting material including at least one of furfural and furfuryl alcohol may be subjected to a direct hydrogenation reaction in a single step to obtain a mixture of <NUM>,<NUM>-pentandiol and <NUM>,<NUM>-pentandiol. The reaction yield of <NUM>,<NUM>-pentandiol may be adjusted depending on the activity of the catalyst component that is used.

The transition metal may be at least one metal selected from among transition metals of Groups <NUM>, <NUM>, <NUM>, and <NUM>, and preferably is at least one selected from among Ru, Pt, Rh, Pd, Ir, Ni, Co, and Cu, or is at least one selected from among Ru, Pt, Ni, Co, and Cu.

The amount of tin may be <NUM> to <NUM> mol%, preferably <NUM> to <NUM> mol%, more preferably <NUM> to <NUM> mol%, and even more preferably <NUM> to <NUM> mol%, based on the total amount of the catalytically active material.

A heterogeneous catalyst system in which the catalytically active metal is supported on the support is preferable, and the support, which is basic, may include alkali metal oxide, alkaline earth metal oxide, lanthanide oxide, zinc oxide, spinel, perovskite, hydrotalcite, calcium silicate, basic zeolite, basic metal organic frameworks (MOFs), etc. Examples of the basic support may include MgO, CaO, BaO-ZnO, MgO-Al<NUM>O<NUM>, ZnO, ZrO<NUM>, CeO<NUM>, hydroxyapatite, Mg<NUM>Al<NUM>O<NUM>, ZnAl<NUM>O<NUM>, BaTiO<NUM>, ZnTiO<NUM>, Cs<NUM>O, CsX (in which X = OH, Cl, Br, or I), Zr-based MOFs, Mg-based MOFs, Ca-based MOFs, Sr-based MOFs, Ba-based MOFs, Mg<NUM>Al<NUM>O<NUM>, ZnAl<NUM>O<NUM>, BaTiO<NUM>, ZnTiO<NUM>, and the like, but are not limited thereto, so long as the support is basic.

The support is preferably at least one selected from among ZnO, MgO, CeO<NUM> and ZrO<NUM>, and more preferably includes ZnO or MgO.

The catalytically active metal is preferably supported in an amount of <NUM> to <NUM> wt% on the support, and when the amount of the catalytically active metal falls within the above range, an optimal effect is exhibited between the catalytic activity and the supported amount.

In a method of preparing the catalyst system in which the catalytically active metal is supported on the support, a support may be formed first, and an active metal precursor may be supported through an impregnation process, or a material used as the support and a catalytically active metal precursor may be simultaneously coprecipitated, and thus the catalytically active metal may be supported.

The type of precursor of the transition metal in the active metal is not particularly limited, but at least one selected from among halogen salts, nitrates, oxalates, carbonates, sulfates, nitrosyl acetate and nitrosyl nitrate may be used.

The type of precursor of tin, which is contained in the active metal of the present disclosure, is not particularly limited, but at least one selected from among Sn(NO<NUM>)<NUM>, SnCl<NUM>, SnCl<NUM>, Sn(OC(CH<NUM>)<NUM>)<NUM>, SnCl<NUM>·<NUM><NUM>O, SnBr<NUM>, SnI<NUM>, Sn(OH)<NUM>, SnSO<NUM>, Sn(CH<NUM>COO)<NUM>, Sn(CH<NUM>COCHCOCH<NUM>)<NUM>, SnO, SnO<NUM>, and Sn<NUM>(PO)<NUM> may be used.

The method of preparing the catalyst system in which the catalytically active metal containing the transition metal and tin (Sn) is supported on the basic support, includes a) preparing a support solution by dispersing a support in water or an organic solvent, b) adding precursors of a transition metal and tin as active components to the support solution and then performing stirring, c) drying the resulting catalyst precursor solution to obtain a dried product, d) firing the dried product to obtain a fired product, and e) reducing the fired product to obtain a catalyst system on which the catalytically active metal is supported.

Here, step a) may be replaced with a') preparing a solution in which precursors of a transition metal and tin, as active components, are dissolved, and step b) may be replaced with b') dispersing a support in the solution in which the transition metal precursor and the tin precursor are dissolved. Steps a) and b) may be performed simultaneously, so the support and the active component metal precursors may be added simultaneously.

The precursors of step b) or b') may be directly added to the solution of step a) or a'), or the precursors of step b) or b') may be dissolved in individual solvents, and the dissolved solutions may then be added to the solution of step a) or a').

The firing of step d) may be omitted, and step e) may be performed immediately.

In addition, a method of preparing a catalyst includes i) preparing a solution in which a precursor of a material used as a support and precursors of a transition metal and tin as active metal components are weighed and dissolved in a solvent, ii) adjusting the pH of the solution, iii) aging the solution after step ii) at a predetermined temperature, iv) subjecting a precipitate in the solution after step iii) to filtering, selective washing, and drying, v) firing the dried precipitate, and vi) reducing the fired product.

In step i), the precursor of the material used as the support and the precursors of metals used as the active metal components may be simultaneously added to the solvent to prepare a solution, or solutions obtained by individually dissolving the precursors may be mixed together. Here, the mixing sequence is that the active metal precursors may be mixed first and then mixed with the precursor of the material used as the support, or conversely, the solution of the precursor of the material used as the support may be mixed with the active metal precursors. The support precursor and the transition metal precursor may be mixed first, and then the tin precursor may be added thereto, or the support precursor and the tin precursor may be mixed first, and then the transition metal precursor may be added thereto, and there may be variations in the mixing sequence. However, when step i) is not a single step but is sequential mixing, adjusting the pH in step ii) may be performed after sequential mixing, and the aging of step iii) may be performed after final mixing, or may be performed after mixing in each step.

Therefore, in the preparation sequence of the catalyst, steps i), ii) and iii) may be repeated as needed, and thus may progress in the sequence of i) → ii) → iii) → i) → ii) → iii). vi) → v) → vi), or in the sequence of i) → ii) → i) → ii). iii) → vi) → v) → vi). Here, the firing of step v) may be omitted, and the reducing of step vi) may be performed immediately.

The aging may be performed in a manner in which the solution is allowed to stand in the state in which heat is applied thereto, or is allowed to stand without separate heating.

For the adjustment of the pH, a basic material or an acidic material may be used, and NaOH is preferably used.

Moreover, the reduction step is performed through reduction in a liquid phase using a reducing agent such as hydrazine, NaBH<NUM>, etc. or through heat treatment in a hydrogen atmosphere, which controls the dispersion degree and specific surface area of the active metal, removes impurities from the catalyst, and increases bonding strength between the active metal and the support. This step is preferably conducted in the temperature range of room temperature to <NUM>.

In the reduction step, all of the metals present in the catalytically active metal may be reduced, or only some thereof may be reduced. For example, when Ru and Sn are used as active metal components, Ru may be in the form of being reduced to a metal, but Sn may be present in a form such as Sn<NUM>+, Sn<NUM>+, etc. in which a portion of Sn is not reduced to a metal but is bound with oxygen, etc. Also, the transition metal and Sn contained in the catalytically active metal may be provided in the form of an alloy.

The results of measurement of XRD to confirm the state after reduction of the catalytically active metal are shown in <FIG>. With reference to <FIG>, it can be seen that, when only Ru is supported on ZnO, the alloy phase of Ru and Sn does not appear, but when both Ru and Sn are supported simultaneously, the metal alloy phase such as Ru<NUM>Sn<NUM> is present.

In addition, a method of preparing <NUM>,<NUM>-pentanediol according to the present disclosure includes reacting a starting material including at least one of furfural and furfuryl alcohol with hydrogen in the presence of the catalyst, in which the active metal including at least one transition metal and tin (Sn) is supported on the basic support.

The furfural and/or furfuryl alcohol may be compounds derived from biomass, and specifically may be derived from hemicellulose. The material that occupies most of the hemicellulose is xylan, and furfural may be easily obtained by decomposing xylan into xylose, which is pentose, through hydrolysis, and dehydrating xylose.

The catalyst may be used in an amount of <NUM> to <NUM> wt% based on the amount of the starting material, and if the amount of the catalyst is less than <NUM> wt%, sufficient catalytic activity may not appear, whereas if the amount of the catalyst exceeds <NUM> wt%, economic benefits may be negated in view of the effect of increasing the catalytic activity depending on the amount of the catalyst.

When a starting material such as furfural and/or furfuryl alcohol is reacted with hydrogen using the catalyst of the present disclosure, in which the active metal including at least one transition metal and tin (Sn) is supported on the basic support, the reaction yield of <NUM>,<NUM>-pentanediol increases.

The reaction yield of <NUM>,<NUM>-pentanediol is preferably <NUM>% or more, more preferably <NUM>% or more, and most preferably <NUM>% or more.

The reaction in the presence of the catalyst may proceed in a liquid phase or a gas phase.

When the reaction in the presence of the catalyst proceeds in a liquid phase, the reaction is preferably carried out under conditions of a reaction temperature of <NUM> to <NUM> and a hydrogen pressure of <NUM> to <NUM> bar. If the hydrogen pressure is less than <NUM> bar, the reaction rate may be slow, whereas if the hydrogen pressure exceeds <NUM> bar, the reaction yield of byproducts may increase and thus the reaction yield of <NUM>,<NUM>-pentanediol may decrease, which is undesirable.

When the reaction of the present disclosure proceeds in a liquid phase, the starting material is reacted in a state in which the liquid phase is maintained, and the starting material may be used by being diluted in a solvent capable of dissolving the starting material. Here, the solvent is preferably used in an amount of <NUM> to <NUM> wt%, and more preferably <NUM> to <NUM> wt%, based on the amount of the starting material. Unlimited examples of the solvent may include alcohol, GBL (gamma-butyrolactone), water, and mixtures thereof. Preferably, the solvent is an alcohol, and is more preferably <NUM>-propanol, isopropanol, <NUM>-butanol, <NUM>-butanol, or mixtures thereof.

Since the alcohol solvent has high solubility of furfural and furfuryl alcohol and does not contain a highly reactive site, it does not cause changes in functional groups or in rapid chemical properties in the reaction with hydrogen, and thus constant reaction conditions may be provided during the reaction process.

When the reaction in the presence of the catalyst proceeds in a gas phase, the reaction is preferably carried out under conditions of a reaction temperature of <NUM> to <NUM> and a hydrogen pressure of <NUM> to <NUM> bar. If the hydrogen pressure is less than <NUM> bar, the reaction rate may be slow, whereas if the hydrogen pressure exceeds <NUM> bar, the reaction yield of byproducts may increase and thus the reaction yield of <NUM>,<NUM>-pentanediol may decrease, which is undesirable.

The reaction in the presence of the catalyst may take place in a reactor through which a gas stream continuously flows. The gas stream in the reactor includes the starting material (including furfural and/or furfuryl alcohol), hydrogen, and optionally, an inert gas, and the gas hourly space velocity (GHSV) of the gas stream relative to the volume of the catalyst is <NUM> to <NUM>,<NUM>-<NUM>, and preferably <NUM> to <NUM>-<NUM>. If the gas hourly space velocity of the gas stream is less than <NUM>-<NUM>, the reaction proceeds well, but the amount of the product is too small, which is undesirable in view of industrial applicability.

The reactor in the presence of a heterogeneous catalyst in a gas phase is a tubular reactor packed with a heterogeneous catalyst.

A feed stream injected into the tubular reactor via suitable metering devices is composed of a starting material including at least one selected from the group consisting of furfuryl alcohol and furfural, the required amount of hydrogen, and, optionally, an inert gas. The starting material may be converted into a gas phase using a saturator for heating liquid furfuryl alcohol and/or furfural to a temperature of <NUM> to <NUM>, preferably <NUM> to <NUM>, and flows of hydrogen or hydrogen and an inert gas may be used by passing through the liquid starting material, or the liquid starting material may be placed in an evaporator using a metering pump or the like and thus vaporized and used.

A better understanding of the catalyst for preparing <NUM>,<NUM>-pentanediol and the reaction for preparing <NUM>,<NUM>-pentanediol using the same may be obtained through the following preparation examples and experimental examples.

In the following description of preferred embodiments of the present disclosure, detailed descriptions of known functions and components incorporated herein will be omitted when the same may make the subject matter of the present disclosure unclear.

<NUM> wt% Ru/ZnO was prepared through precipitation and deposition as follows.

Zn(NO<NUM>)<NUM>·<NUM><NUM>O was used as a Zn precursor, and RuCl<NUM>·xH<NUM>O was used as a Ru precursor. Zn(NO<NUM>)<NUM>·<NUM><NUM>O and RuCl<NUM> ·xH<NUM>O were weighed such that the mass converted to Ru became <NUM> wt% of the mass converted to ZnO, and an aqueous solution in which these precursors were dissolved in distilled water was stirred for <NUM> hours while the pH thereof was maintained at <NUM>-<NUM> through dropwise addition of a <NUM> NaOH solution at room temperature, and was then allowed to stand at <NUM> for <NUM> hours.

Thereafter, a precipitate in the solution was filtered and then fired at <NUM> for <NUM> hours in an ambient atmosphere. The fired catalyst was reduced at <NUM> for <NUM> hours in a <NUM>% H<NUM>/N<NUM> atmosphere before use for the reaction.

The alloy catalyst of Ru and Sn was prepared through coprecipitation and deposition as follows.

Zn(NO<NUM>)<NUM>·<NUM><NUM>O, SnCl<NUM>·<NUM><NUM>O and RuCl<NUM> ·xH<NUM>O were weighed such that the total mass of Ru and Sn metals was <NUM> wt% relative to the mass of ZnO. Here, the molar ratio of Ru and Sn was adjusted to <NUM>:<NUM> (Preparation Example <NUM>), <NUM>:<NUM> (Preparation Example <NUM>) or <NUM>:<NUM> (Preparation Example <NUM>).

The weighed Zn(NO<NUM>)<NUM>·<NUM><NUM>O was dissolved in water to obtain a <NUM> aqueous solution, and the SnCl<NUM>·<NUM><NUM>O was dissolved in water to obtain a <NUM> aqueous solution, after which these aqueous solutions were added dropwise to <NUM> of distilled water at room temperature and then stirred for <NUM> hours while the pH of the solution was maintained at <NUM> using <NUM> NaOH.

To the solution thus obtained, a <NUM> RuCl<NUM> ·xH<NUM>O aqueous solution was added dropwise, followed by stirring for <NUM> hour while maintaining the pH of the solution at <NUM> using <NUM> NaOH. After completion of addition of the <NUM> RuCl<NUM> ·xH<NUM>O aqueous solution, the resulting solution was stirred at room temperature for <NUM> hours and then allowed to stand at <NUM> for <NUM> hours.

Next, the resulting precipitate was filtered, washed with water to remove Na and Cl ions, and then dried at <NUM> for <NUM> hours, and the dried product was reduced at <NUM> for <NUM> hours in a <NUM>% H<NUM>/N<NUM> atmosphere before use for the reaction.

<NUM> of hydrotalcite was placed in a solution in which <NUM> of H<NUM>PtCl<NUM>·xH<NUM>O was dissolved in <NUM> of distilled water, and excess water was evaporated at <NUM> using a rotary evaporator, followed by firing at <NUM> for <NUM> hours in an ambient atmosphere to obtain a <NUM> wt% Pt/hydrotalcite catalyst. The catalyst was reduced at <NUM> for <NUM> hours in a <NUM>% H<NUM>/N<NUM> atmosphere before use for the reaction.

Mg-Al hydrotalcite (Mg/Al=<NUM>) was prepared through coprecipitation. <NUM> of Mg(NO<NUM>)<NUM>·<NUM><NUM>O and <NUM> of Al(NO<NUM>)<NUM>·<NUM><NUM>O were added to <NUM> of deionized water, and to the resulting solution, <NUM> of a <NUM> Na<NUM>CO<NUM> aqueous solution was slowly added so that precipitation proceeded. The pH of the solution was adjusted to <NUM> using <NUM> NaOH. The resulting precipitate was allowed to stand at <NUM> for <NUM> hours and then washed with deionized water until the filtered solution became neutral. The filtered solid was dried at <NUM> for <NUM> hours and then fired at <NUM> for <NUM> hours using steam. The fired sample was again added to <NUM> of deionized water, followed by sonication while allowing nitrogen to flow at <NUM> for <NUM> hours. The solid was filtered and then dried at <NUM> for <NUM> hours to obtain Mg-Al hydrotalcite.

The Mg-Al hydrotalcite thus obtained was placed in an aqueous solution of SnCl<NUM>·<NUM><NUM>O and RuCl<NUM>·xH<NUM>O weighed such that the total mass converted to Ru and Sn was <NUM> wt%, after which Ru and Sn were supported through coprecipitation. Here, the molar ratio of Ru and Sn was adjusted to <NUM>:<NUM>. Excess water was evaporated at <NUM> using a rotary evaporator. The catalyst was dried for <NUM> hours in an ambient atmosphere and then reduced at <NUM> for <NUM> hours in a <NUM>% H<NUM>/N<NUM> atmosphere.

Supporting was performed in the same manner as in Preparation Example <NUM>, with the exception that Pt was used in lieu of Ru. Here, the Pt precursor that was used was H<NUM>PtCl<NUM>·xH<NUM>O.

The alloy catalyst of Ni and Sn was prepared through coprecipitation as follows.

Zn(NO<NUM>)<NUM>·<NUM><NUM>O, SnCl<NUM>·<NUM><NUM>O and Ni (NO<NUM>)<NUM>·<NUM><NUM>O were weighed such that the total mass of Ni and Sn metals was <NUM> wt% relative to the mass of ZnO. Here, the molar ratio of Ni and Sn was adjusted to <NUM>:<NUM>.

Specifically, <NUM> of Zn(NO<NUM>)<NUM>·<NUM><NUM>O and <NUM> of SnCl<NUM>·<NUM><NUM>O were dissolved in <NUM> of distilled water and <NUM> of distilled water, respectively, and then these two solutions were mixed together. The resulting solution was mixed with <NUM> of a <NUM> Ni (NO<NUM>)<NUM>·<NUM><NUM>O aqueous solution and then stirred for <NUM> hours while the pH of the solution was maintained at <NUM> using <NUM> NaOH.

After further stirring at <NUM> for <NUM> hours, the resulting precipitate was filtered, washed with water to remove Na and Cl ions, dried at <NUM> for <NUM> hours, and fired at <NUM> for <NUM> hours, and the dried product was reduced at <NUM> for <NUM> hours in a <NUM>% H<NUM>/N<NUM> atmosphere before use for the reaction.

A <NUM> wt% 1Ru-5Sn/support was prepared by mixing Ru and Sn precursors in the same manner as above, with the exception of using SiO<NUM> (Preparation Example <NUM>) and Al<NUM>O<NUM> (Preparation Example <NUM>) as the support using a wet impregnation process. Here, hydrotalcite, SnCl<NUM>·<NUM><NUM>O and RuCl<NUM>·xH<NUM>O were weighed such that the total mass of Ru and Sn metals was <NUM> wt% relative to the mass of the support SiO<NUM> or Al<NUM>O<NUM>. The molar ratio of Ru and Sn was adjusted to <NUM>:<NUM>. The catalyst was reduced at <NUM> for <NUM> hours in a <NUM>% H<NUM>/N<NUM> atmosphere before use for the reaction.

First, <NUM> of a Ludox-SM30 (<NUM>) aqueous solution and <NUM> of SnCl<NUM>·<NUM><NUM>O (<NUM>) were mixed and then slowly mixed (dropwise) while the pH thereof was maintained at <NUM> using <NUM> NaOH. The mixed solution was stirred at room temperature for <NUM> hours and then allowed to stand at <NUM> for <NUM> hours, after which the resulting precipitate was filtered, washed with distilled water, dried, and then fired in air at <NUM> to obtain (<NUM>:<NUM>)SnO<NUM>-SiO<NUM> at a mass ratio of SnO<NUM> and SiO<NUM> of <NUM>:<NUM>.

The (<NUM>:<NUM>)SnO<NUM>-SiO<NUM> thus obtained was placed in an aqueous solution of RuCl<NUM>·xH<NUM>O weighed such that the mass converted to Ru was <NUM> wt%, and Ru was supported through impregnation. Excess water was evaporated at <NUM> using a rotary evaporator.

The <NUM> wt% Ru/(<NUM>:<NUM>)SnO<NUM>-SiO<NUM> thus obtained was fired at <NUM> for <NUM> hours in an ambient atmosphere, and the fired catalyst was reduced at <NUM> for <NUM> hours in a <NUM>% H<NUM>/N<NUM> atmosphere before use for the reaction.

<NUM> wt% Cu/(<NUM>:<NUM>)SnO<NUM>-SiO<NUM> was prepared in the same manner as in Preparation Example <NUM>, with the exception that Cu(NO<NUM>)<NUM>·<NUM><NUM>O, weighed such that the mass of Cu metal was <NUM> wt% relative to the mass of (<NUM>:<NUM>)SnO<NUM>-SiO<NUM>, was used in lieu of RuCl<NUM>·xH<NUM>O.

Cu(NO<NUM>)<NUM>·<NUM><NUM>O, Ni(NO<NUM>)<NUM>·<NUM><NUM>O, and SnCl<NUM>·<NUM><NUM>O were weighed such that the total mass of Cu, Ni and Sn metals was <NUM> wt% relative to the mass of SiO<NUM>. Then, the same procedures were performed as in Preparation Example <NUM>, with the exception that the molar ratio of (Cu+Ni) and Sn was set to <NUM>:<NUM> and the molar ratio of Cu and Ni was adjusted to <NUM>:<NUM>, thereby obtaining <NUM> wt% <NUM>(Cu-Ni)-5Sn/SiO<NUM>.

Using the catalysts prepared in Preparation Examples above, an experiment for the preparation of <NUM>,<NUM>-pentanediol was carried out as follows.

Into a <NUM> stainless steel autoclave reactor equipped with a Teflon container, <NUM> of the catalyst prepared in each of Preparation Examples above, <NUM> of anhydrous isopropanol and <NUM> of furfural were added and purged with hydrogen three times or more to replace the atmosphere in the container with hydrogen. After applying the pressure with high-pressure hydrogen and raising the temperature to the reaction temperature, the reaction was carried out for a predetermined time. Here, stirring was performed using a Teflon magnetic bar at a stirring speed of <NUM> rpm. The hydrogen pressure, the reaction temperature, and the reaction time are shown in Table <NUM> below.

After the reaction, the temperature was lowered to room temperature, the catalyst was removed through simple filtration, and the solution in the reactor was collected and analyzed by GC (FID) using a CycloSil-B column (<NUM> X <NUM> X <NUM> µm). The results thereof are shown in Table <NUM> below.

Table <NUM> below shows the results of calculation of the reaction yield of <NUM>,<NUM>-pentanediol synthesized through reaction with hydrogen using the catalyst prepared in Preparation Example.

In Table <NUM> below, furfural conversion% and C Yield were calculated as follows. <MAT><MAT>.

As is apparent from Table <NUM>, when using the catalyst in which <NUM> wt% of ruthenium was supported alone as a transition metal (Preparation Example <NUM>), the reaction of <NUM>,<NUM>-pentanediol did not occur, but when using the catalyst in which both ruthenium and tin were supported in a total weight of <NUM> wt% (Preparation Examples <NUM> to <NUM>), the production of <NUM>,<NUM>-pentanediol was confirmed even though the amount of the active metal that was supported was decreased. The reactivity also differs depending on the relative molar ratio of ruthenium and tin. When the molar ratio of tin/ruthenium was increased from <NUM> to <NUM>, the reaction yield of <NUM>,<NUM>-pentanediol was greatly increased from <NUM>% to <NUM>% despite the short reaction time under the same conditions.

In addition, even with the same active metal, when using the basic support such as ZnO or hydrotalcite, the yield of <NUM>,<NUM>-pentanediol was much higher than when using the support such as silica or alumina, indicating that not only the type of active metal but also the properties of the support are regarded as very important in the present catalyst system.

Specifically, all of a solution of <NUM> of Zn(NO<NUM>)<NUM>·<NUM><NUM>O in <NUM> of distilled water, a solution of <NUM> of Ni(NO<NUM>)<NUM>·<NUM><NUM>O in <NUM> of distilled water, and <NUM> of SnCl<NUM>·<NUM><NUM>O in <NUM> of distilled water were slowly added dropwise to <NUM> of distilled water and mixed together. Here, the pH of the solution was maintained at <NUM>-<NUM> through dropwise addition of <NUM> NaOH. After formation of the precipitate, the solution was stirred at room temperature for <NUM> hours.

Thereafter, the solution was further stirred at room temperature for <NUM> hours and allowed to stand at <NUM> for <NUM> hours, after which the resulting precipitate was filtered, washed with water to remove Na and Cl ions, dried at <NUM> for <NUM> hours in an ambient atmosphere, and compressed and pulverized. The particles having a size of <NUM> to <NUM> were sieved, the particles thus obtained were fired at <NUM> for <NUM> hours in an ambient atmosphere, and the fired product was reduced at <NUM> for <NUM> hours in a <NUM>% H<NUM>/N<NUM> (<NUM> cc/ min) atmosphere before use for the reaction.

<NUM> wt% 1Cu-1Sn/ZnO was prepared in the same manner as in Preparative Example <NUM>, with the exception that Cu(NO<NUM>)<NUM>·<NUM><NUM>O (<NUM> in <NUM> of H<NUM>O) was used in lieu of Ni(NO<NUM>)<NUM>·<NUM><NUM>O (<NUM> in <NUM> of H<NUM>O), SnCl<NUM>·<NUM><NUM>O (<NUM> in <NUM> of H<NUM>O) was used in lieu of SnCl<NUM>·<NUM><NUM>O (<NUM> in <NUM> of H<NUM>O), and final reduction was performed at <NUM>.

<NUM> wt% 1Co-1Sn/ZnO was prepared in the same manner as in Preparative Example <NUM>, with the exception that Co(NO<NUM>)<NUM>·<NUM><NUM>O (<NUM> in <NUM> of H<NUM>O) was used in lieu of Ni(NO<NUM>)<NUM>·<NUM><NUM>O (<NUM> in <NUM> of H<NUM>O), SnCl<NUM>·<NUM><NUM>O (<NUM> in <NUM> of H<NUM>O) was used in lieu of SnCl<NUM>·<NUM><NUM>O (<NUM> in <NUM> of H<NUM>O), and final reduction was performed at <NUM>.

Zn(NO<NUM>)<NUM>·<NUM><NUM>O, SnCl<NUM>·<NUM><NUM>O and RuCl<NUM>·xH<NUM>O were weighed such that the total mass of Ru and Sn metals was <NUM> wt% relative to the mass of ZnO. Here, the molar ratio of Ru and Sn was adjusted to <NUM>:<NUM>.

The weighed Zn(NO<NUM>)<NUM>·<NUM><NUM>O was dissolved in water to obtain a <NUM> aqueous solution, the SnCl<NUM>·<NUM><NUM>O was dissolved in water to obtain a <NUM> aqueous solution, these aqueous solutions were then added dropwise to <NUM> of distilled water at room temperature, and the pH of the solution was maintained at <NUM> using <NUM> NaOH. After precipitation and then stirring for <NUM> hours, a <NUM> RuCl<NUM>·xH<NUM>O aqueous solution was added dropwise to the solution stirred above, and the pH of the solution was maintained at <NUM> using <NUM> NaOH. After completion of addition of the <NUM> RuCl<NUM>·H<NUM>O aqueous solution, the resulting solution was stirred at room temperature for <NUM> hours and then allowed to stand at <NUM> for <NUM> hours.

Next, the resulting precipitate was filtered, washed with water to remove Na and Cl ions, dried at <NUM> for <NUM> hours in an ambient atmosphere, and compressed and pulverized, and the particles having a size of <NUM> to <NUM> were sieved. The dried product thus obtained was reduced through direct reduction without firing.

<NUM> wt% Ni/ZnO was prepared in the same manner as in Preparative Example <NUM>, with the exception that a Ni precursor was used alone, without the use of the Sn precursor, and Ni (NO<NUM>)<NUM>·<NUM><NUM>O, weighed such that the mass of Ni metal was <NUM> wt% relative to the mass of ZnO, was supported.

<NUM> wt% 1Ni-1Sn/γ-Al<NUM>O<NUM> was prepared in the same manner as in Preparative Example <NUM>, with the exception that γ-Al<NUM>O<NUM> (<NUM>) was used as the support.

<NUM> wt% 1Ni-1Sn/CeO<NUM> was prepared in the same manner as in Preparative Example <NUM>, with the exception that an aqueous solution (<NUM>/<NUM>) of Ce(NO<NUM>)<NUM>·<NUM><NUM>O as a support precursor was slowly added dropwise to <NUM> of an aqueous solution along with Ni and Sn and mixed together.

Using the catalysts prepared in Preparation Examples above, an experiment for the preparation of <NUM>,<NUM>-pentanediol by reacting furfuryl alcohol with hydrogen in a gas phase was carried out as follows.

The measurement of the activity of the catalyst was performed in a fixed-bed downstream stainless steel (SUS <NUM>) reactor under pressure. The preheating zone was kept at <NUM> to evaporate furfuryl alcohol. The catalyst (<NUM>) was located in the middle portion of the reactor using quartz wool as a support. The reaction was carried out at <NUM>-<NUM>, and the hydrogen pressure was monitored using a pressure regulator connected to the reactor and a hydrogen gas line. Furfuryl alcohol was mixed at <NUM> wt% in isopropyl alcohol and introduced into the reactor at a WHSV of <NUM> using a liquid metering pump along with hydrogen (at a flow rate of <NUM> cc/min).

The gas components of the reaction mixture (H<NUM> and gaseous hydrocarbon) were analyzed by TCD using on-line gas chromatography (Donam Instruments DS6200) equipped with a carbon sphere capillary tube. <NUM>,<NUM>-pentanediol (<NUM>,<NUM>-PDO), <NUM>,<NUM>-pentanediol (<NUM>,<NUM>-PDO), methyltetrahydrofuran, tetrahydrofurfuryl alcohol (THFA), <NUM>-methylfuran (2MF), <NUM>-methyltetrahydrofuran (MTHF), <NUM>-pentanol (PO), <NUM>,<NUM>-pentanediol (<NUM>,<NUM>-PDO), tetrahydrofuran (THF), etc. were collected every <NUM> hours and detected using a flame ionization detector (FID), CycloSil-B column (<NUM> X <NUM>), and HP-<NUM>. The carbon mass balance of the liquid product was estimated to be <NUM>% or more. The catalyst performance was evaluated based on the furfuryl alcohol conversion and the yield of <NUM>,<NUM>-PDO.

The results of catalytic activity are shown in Table <NUM> below.

In Table <NUM> below, furfuryl alcohol conversion was calculated by substituting the number of moles of furfuryl alcohol in lieu of furfural into Equation <NUM>, and C Yield was calculated as in Equation <NUM>.

As is apparent from Table <NUM>, all the catalysts that were used exhibited a furfuryl alcohol conversion of <NUM>% under the experimental conditions, but the product distribution differed depending on experimental conditions such as temperature, pressure and the type of catalyst that was used.

In the experimental example using the catalyst of Preparation Example <NUM>, the highest yield of <NUM>,<NUM>-PDO was obtained when the reaction temperature was <NUM>, and the yield of <NUM>,<NUM>-PDO was also increased when the hydrogen pressure increased from <NUM> bar to <NUM> bar.

In addition, the yield of <NUM>,<NUM>-PDO in the gas-phase catalytic reaction was the highest in the presence of the catalyst prepared in Preparation Example <NUM>.

When comparing the reaction experiment results using the catalysts of Preparation Example <NUM> and Preparation Example <NUM>, the yield of <NUM>,<NUM>-PDO was higher before the addition of Sn, but the yield of <NUM>,<NUM>-PDO was greatly increased in the presence of the catalyst of Preparation Example <NUM> to which Sn was added, indicating that the presence of Sn is essential for the conversion of furfuryl alcohol into <NUM>,<NUM>-PDO.

Claim 1:
A method of preparing <NUM>,<NUM>-pentanediol through a hydrogenation reaction of a starting material comprising at least one of furfural and furfuryl alcohol in presence of a catalyst,
wherein the catalyst is configured such that a catalytically active metal is supported on a basic support, and the catalytically active metal comprises tin and at least one transition metal as an additional metal
wherein the basic support is at least one selected from among alkali metal oxide, alkaline earth metal oxide, lanthanide oxide, zinc oxide, spinel, perovskite, hydrotalcite, calcium silicate, MgO, CaO, BaO-ZnO, MgO-Al<NUM>O<NUM>, ZnO, ZrO<NUM>, CeO<NUM>, hydroxyapatite, Mg<NUM>Al<NUM>O<NUM>, ZnAl<NUM>O<NUM>, BaTiO<NUM>, ZnTiO<NUM> , Cs<NUM>O, CsX (wherein X = OH, Cl, Br, or I), Zr-based MOFs, Mg-based MOFs, Ca-based MOFs, Sr-based MOFs, Ba-based MOFs, Mg<NUM>Al<NUM>O<NUM>, ZnAl<NUM>O<NUM>, BaTiO<NUM>, and ZnTiO<NUM>.