Ir₁Zn _n Bimetallic Site for Efficient Production of Hydrogen from Methanol

Methanol partial oxidation is an extremely promising route of realizing the hydrogen production for onboard such as in automobiles. Here, we report the design of a catalyst comprising isolated singly dispersed Ir₁Zn_n sites and their support ZnO (Ir₁Zn_n/ZnO), which exhibits high catalytic activity in terms of turnover frequency of producing 13.0 H₂ molecules from each Ir₁Zn_n site per second. The selectivities for H₂ and CO₂ productions on Ir₁Zn_n/ZnO are 99% at 310 °C, respectively. Compared to catalysts of bimetallic nanoparticle supported on ZnO (Ir-Zn/ZnO), the singly dispersed Ir₁Zn_n bimetallic sites with Ir atoms at cationic state are responsible for the high activity of this single-atom catalyst. The single dispersion of Ir atoms on this catalyst minimizes choices of binding configurations of reactants or intermediates in contrast to the coexistence of multiple binding sites of Ir atoms and Ir-Zn alloy leading to high selectivities for producing H₂ and CO₂. This study extended the horizontal of bimetallic catalysts through immobilization of isolated bimetallic sites on an inert support.