# Exploring CeO\({}_{2}\)-Doped Co/SBA-15 Catalysts for Acetic Acid Oxidative Steam Reforming
## 1 Introduction
\[\mathrm{CO+H_{2}O\leftrightarrow H_{2}+CO_{2}} \tag{3}\]  
\[\mathrm{C_{2}H_{4}O_{2}\leftrightarrow CH_{4}+CO_{2}} \tag{4}\]  
\[2\;\mathrm{C_{2}H_{4}O_{2}\leftrightarrow C_{3}H_{6}O+CO_{2}+H_{2}O} \tag{5}\]  
\[\mathrm{C_{3}H_{6}O+5H_{2}O\leftrightarrow 8\;H_{2}+3 CO_{2}} \tag{6}\]  
\[\mathrm{CH_{4}+2H_{2}O\leftrightarrow 4\;H_{2}+CO_{2}} \tag{7}\]  
\[\mathrm{CO_{2}+2H_{2}\leftrightarrow 2\;H_{2}O+C} \tag{8}\]  
\[\mathrm{CO+H_{2}\leftrightarrow H_{2}O+C} \tag{9}\]  
\[2\;\mathrm{CO\leftrightarrow CO_{2}+C} \tag{10}\]  
The development of a suitable catalyst to promote selectivity to hydrogen formation is essential because it influences the reaction mechanism and thus is able to enhance the reaction rate toward hydrogen. Catalyst deactivation is still one of the principal issues in the scientific community when referring to reforming catalysts [21] due to the carbon formation or active phase sintering, and in the context of oxidative steam reforming, where an oxidizing environment is present, the active phase reoxidation [18]. Regarding the catalyst formulation, transition metals such as cobalt have been widely used as the active phase [15; 22; 23; 24] in reforming reactions against noble metals, given their promising activity in breaking down C-C and C-H bonds and lower prices. Furthermore, the election of adequate support is crucial for enhancing the active phase dispersion. Previous works [16; 21; 25] have demonstrated that materials based on mesoporous SiO\({}_{2}\), such as SBA-15, used as support, allow higher active phase dispersion due to their highly ordered mesoporous structure with a large surface area. Additionally, it has been reported that the incorporation of CeO\({}_{2}\) into the catalyst formulation improved its activity and resistance toward coke deposition, by the capability of storing, releasing, and transporting oxygen [26]. CeO\({}_{2}\)-SiO\({}_{2}\) supports have been previously studied in steam reforming reactions. In this respect, [PERSON] et al. [27] researched CeO\({}_{2}\)-doped Ni/SiO\({}_{2}\) (Ni/CS) and Ni/SiO\({}_{2}\) (Ni/S) catalysts synthesized via incipient wet impregnation. In this study, it was demonstrated that the H\({}_{2}\)-TPR profiles indicated a slightly lower temperature peak corresponding to NiO reduction for the Ni/CS catalyst, due to the oxygen vacancies in CeO\({}_{2}\), thus facilitating higher reducibility. In catalytic tests on ethanol steam reforming, it was demonstrated that a CeO\({}_{2}\)-doped Ni/SiO\({}_{2}\) catalyst enhanced the catalytic activity, maintaining complete ethanol conversion over time. [PERSON] et al. [28] studied Rh-Pt-based catalysts supported on CeO\({}_{2}\)-SiO\({}_{2}\) for ethanol steam reforming. The CeO\({}_{2}\)-SiO\({}_{2}\) supports were synthesized by the co-precipitation method, and the active phase was incorporated by the incipient wetness co-impregnation method. They determined that the optimum Si content was 33 mol\(\%\), equivalent to a Si:Ce ratio of 2, whereby the highest catalytic yield was obtained, reaching 5.3 mol H\({}_{2}\)/mol EtOH at 700 \({}^{\circ}\)C. [PERSON] et al. [29] evaluated Ce\({}_{0.65}\)Me\({}_{0.1}\)Si\({}_{0.25}\) catalysts (Me = V, Cr, Mn, Nb, W, Mo) in the production of oxygenates from ethanol/steam mixtures. They reported that in CeO\({}_{2}\)-SiO\({}_{2}\) supports, the interactions between silica and surface ceria nanocrystals lead to Ce-O-Si unit formation, promoting increased surface area. Additionally, in Mn and Cr-doped catalysts, an improvement in reducibility was observed, attributed mainly to an increase in CeO\({}_{2}\) oxygen mobility, thus enhancing the catalytic activity. Results showed an initial ethanol conversion close to 90%, with product distribution dominated by hydrogen and a suppressed ethylene formation, promoting a higher catalytic stability for 6 h.  
[PERSON] et al.