Exploring the Reaction Mechanism of Methanol Steam Reforming on CuZn3O3 Cluster: A Density Functional Theory Study.

Hydrogen gas is not only an essential industrial raw material but also an important clean energy. The hydrogen production by methanol steam reforming (MSR) has attracted much attention due to its mild reaction conditions and high hydrogen yield. Herein, the MSR reactions on CuZn3O3 cluster are explored using theoretical calculations. It is found that the adjacent Cu and Zn atoms in CuZn3O3 cluster play the synergistic roles in the MSR reaction. Specifically, the reaction starts with the adsorption of H2O and CH3OH on the Zn atoms. Then, the adsorbed CH3OH and H2O dehydrogenate, and the produced oxygen-containing intermediates (CH3O* and *OH) remain adsorbed on the Zn atoms. The dissociated H atoms migrate to the nearby Cu atoms. In their subsequent dehydrogenation, this rule is still followed. With the participation of H2O, CH2O* combines with OH* to form CH2OOH*, followed by consecutive dehydrogenation to produce CO2 and H2. Moreover, the formate (HCOO*) pathway is the least energy-demanding pathway compared with the carboxyl (COOH*) pathway. The synergistic roles of adjacent Cu and Zn atoms in CuZn3O3 cluster may provide insight into the structure-activity relationship of CuZnO interfacial sites in related MSR catalysts.