Heterogeneous Oxidase-Type Catalysis for H₂ Generation at Low Temperatures

The long-term objective in the field of heterogeneous catalysis is to develop an enzyme-like catalytic pathway that can achieve exceptional catalytic performance even at low temperatures. Herein, we have demonstrated a heterogeneous oxidase-type catalysis on the ZnO-supported Ru clusters (Ru/ZnO) for efficient H2 generation from an aqueous solution of formaldehyde (HCHO) at low temperatures. Due to its unique reaction pathway, the Ru/ZnO catalysts exhibited a temperature-insensitive activity for H2 generation at the temperature of 15 to 45 °C. Remarkably, even at a low temperature of 5 °C, the Ru/ZnO catalysts still enabled an H2 generation rate of 13.8 mmol gcat-1 h-1 with a turnover frequency (TOF) of 1678 h-1. Additionally, instead of producing a CO2/CO molecule, the HCHO molecule underwent a transformation into formic acid and/or formate as the byproduct. This finding presents a novel class of heterogeneous catalysts to expand the potential application scenarios of liquid hydrogen storage and transportation systems.