Probing the catalytic behavior of ZnO nanowire supported Pd1 single-atom catalyst for selected reactions

Abstract

We have dispersed individual Pd atoms onto ZnO nanowires (NWs) as single-atom catalysts (SACs) and evaluated their catalytic performance for several selected catalytic reactions. The Pd1/ZnO SAC is highly active, stable, and selective towards CO2 for steam reforming of methanol to produce hydrogen. This catalyst system is active for oxidation of CO and H2 but performs poorly for preferential oxidation of CO in hydrogen-rich stream primarily due to the strong competitive oxidation of H2 on ZnO supported Pd1 atoms. At ambient pressure, reverse water-gas-shift reaction occurs on the Pd1/ZnO SAC. This series of tests of catalytic reactions clearly demonstrate the importance of selecting the appropriate metal and support to develop SACs for catalytic transformation of molecules.