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

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.