TiO2-supported Ni-Sn as an effective hydrogenation catalyst for aqueous acetic acid to ethanol

• Main Authors: Yuanyuan Zhao, Takayuki Nishida, Eiji Minami, Shiro Saka, Haruo Kawamoto
• Format: Article
• Language: English
• Published: Elsevier 2020-11-01
• Series: Energy Reports
• Subjects: Bioethanol; Ni-Sn/TiO2; Hydrogenation; Acetic acid
• Online Access: http://www.sciencedirect.com/science/article/pii/S2352484720312579

Various Ni and Ni-Sn catalysts supported on TiO2 were prepared and the catalytic activities were evaluated for ethanol formation from aqueous acetic acid. Although catalytic activities of the Ni/TiO2 catalysts were limited, the addition of Sn improved the activity dramatically, and the optimum Ni/Sn ratio was approximately 1:1 (w/w). SnO2, the precursor of Sn, could not be reduced into metal Sn in pure form but did reduce into Ni-Sn alloys in the presence of NiO, the precursor of Ni. Analyses with XRD and SEM-EDS revealed that the Ni-Sn alloys were homogeneously dispersed on the TiO2 surface. Furthermore, IR analysis indicated that the Ti atoms in the catalyst act as a Lewis acid, which coordinates to the oxygen atoms of acetic acid, enhancing the attack of hydrogens activated on neighboring Ni-Sn alloys. Based on these results, Ni-Sn/TiO2 is proposed as an effective hydrogenation catalyst for converting aqueous acetic acid into ethanol.