Atomically Thick Oxide Overcoating Stimulates Low-Temperature Reactive Metal-Support Interactions for Enhanced Catalysis

Reactive metal-support interactions (RMSIs) induce the formation of bimetallic alloys and offer an effective way to tune the electronic and geometric properties of metal sites for advanced catalysis. However, RMSIs often require high -temperature reductions (>500 degrees C), which significantly limits the tuning of bimetallic compositional varieties. Here, we report that an atomically thick Ga2O3 coating of Pd nanoparticles enables the initiation of RMSIs at a much lower temperature of similar to 250 degrees C. State-of-the-art microscopic and in situ spectroscopic studies disclose that low-temperature RMSIs initiate the formation of rarely reported Ga-rich PdGa alloy phases, distinct from the Pd2Ga phase formed in traditional Pd/Ga2O3 catalysts after high temperature reduction. In the CO2 hydrogenation reaction, the Ga-rich alloy phases impressively boost the formation of methanol and dimethyl ether similar to 5 times higher than that of Pd/Ga2O3. In situ infrared spectroscopy reveals that the Ga-rich phases greatly favor formate formation as well as its subsequent hydrogenation, thus leading to high productivity.

Automated summary

Reactive metal-support interactions (RMSIs) can be initiated at a much lower temperature by using an atomically thick Ga2O3 coating of Pd nanoparticles. This leads to the formation of rarely reported Ga-rich PdGa alloy phases, which significantly enhance the catalytic activity in CO2 hydrogenation reaction. In situ infrared spectroscopy reveals that the Ga-rich phases favor formate formation and its subsequent hydrogenation, resulting in high productivity.