Aqueous-phase reforming of methanol to hydrogen over CoAl oxide-supported Pt catalyst

Abstract

A series of CoAl oxide-supported Pt catalysts (Pt/CoxAl, x = Co/Al ratio) was developed for aqueous-phase reforming of methanol to H2. CoxAl oxides were prepared by calcining layered double hydroxides at different temperatures. The catalytic performance of Pt/CoxAl highly depends on the Co/Al ratio and the calcination temperature. The most active Pt/Co2Al catalyst calcined at 700 °C showed an H2 production rate of 3372 µmolH2·g−1catalyst·min−1 with low CO selectivity. The intense interaction between Pt and support and abundant oxygen vacancies results in high catalytic performance. Intensive characterization and mechanism study reveal that both Pt0 and metallic Co0 promote methanol decomposition. At the same time, H2O is activated on the support and reacts with CO to generate intermediate formate species that are further converted into CO2 and H2.