## 1 Introduction  
Hydrogen is considered one of the best energy carriers to satisfy the ever-growing demand for a clean and sustainable energy supply with the continuous reduction of fossil fuels [1; 2; 3]. However, the controlled storage and release of hydrogen is still a critical, challenging, and urgently required issue for fuel cell based hydrogen economy [4; 5; 6]. Recently among hydrogen-storage materials for mobile applications, methanol, which is readily available and considered as a sustainable energy carrier since it can be produced from renewable sources, has been recognized as a good feedstuff for high-purified hydrogen production due to its high hydrogen/carbon ratio and safe handling [7; 8; 9; 10; 11]. Moreover [3; 4], methanol has no C-C bonds, and can be reformed at a relatively low temperature (200-300 \({}^{\circ}\)C) with low risk of coke formation. Although methanol is highly toxic and miscible in water, it has the advantage of being biodegradable, liquid at atmospheric conditions, and has a high hydrogen to carbon ratio [12]. During the reaction, this range of temperatures is very low when compared to other common fuels such as methane, which is reformed above 500 \({}^{\circ}\)C, and ethanol with a reforming temperature around 400 \({}^{\circ}\)C [13; 14]. Therefore, methanol is considered as one of the most promising sources for hydrogen production via the steam reforming of methanol (SRM): CH\({}_{3}\)OH + H\({}_{2}\)O \(\rightleftharpoons\) CO\({}_{2}\) + 3H\({}_{2}\), \(\Delta\)H\({}^{\circ}\) = 49.5 kJ\(\cdot\)mol\({}^{-1}\)[15; 16; 17]. Recently, a lot of metal catalyst systems, which are divided into two main groups--copper-based and groups 8-10 metal-based catalysts--were tested for hydrogen generation from the steam reforming of methanol [11,18]. Although copper-based catalysts are the most commonly used for the methanol steam reforming reaction (MSR) due to their high activity and selectivity, it is well known that these catalysts can be deactivated by thermal sintering. Thus, it is required to search for other types of catalysts [19, 20, 21, 22, 23]. In comparison to Cu-based, group 8-10 catalysts are highly stable and possess similar selectivity. However, the catalytic activity of the latter catalysts has the disadvantage of producing less hydrogen than the copper-based ones [18,24, 25, 26]. Montmorillonite is the most popular type of clay applied in pillaring processes and at the same time has attracted worldwide attention recently as a particular fascinating material [26]. Clays are low-cost, abundant natural materials and present many advantages, e.g., recyclability, large surface areas and high exchange capacities. Many industrial processes use clay-based catalysts [27]. Natural bentonite (Ben) is a calcium montmorillonite. Compared with Ca-bentonite, Na-bentonite has higher cation exchange capacity, slower adsorption rate, and larger expansion potential. In addition, the colloids of Na-bentonite show better dispersion and thermal stability [28,29]. One of the methods for preparing this kind of material is to prepare the metal nanoparticles supported on an inorganic pillared clay [30,31]. The cationic layered clays can be transformed into highly porous structures by exchanging interlayer charge compensating cations with large inorganic polymeric oxy-hydroxy cationic species [32, 33, 34]. Deposition of such pillars into the interlayer space resulted in a significant increase of the surface area and microporosity of the clay materials [35]. The hydroxyl polycations of polynuclear metals, such as Al, Zr, Ti, Cr, and Fe, are types of inorganic pillaring agents currently being widely studied [36,37]. The TiO\({}_{2}\)-pillared clays have large pore sizes allowing further incorporation of active ingredients without hindering pore diffusion and have high thermal and hydrothermal stability, and also show good catalytic performances [38]. As a kind of clay, bentonite has been widely used in many industries as filter material, adsorbent etc. [39].