Patterning the consecutive Pd3 to Pd1 on Pd2Ga surface via temperature-promoted reactive metal-support interaction

Atom-by-atom control of a catalyst surface is a central yet challenging topic in heterogeneous catalysis, which enables precisely confined adsorption and oriented approach of reactant molecules. Here, exposed surfaces with either consecutive Pd trimers (Pd3) or isolated Pd atoms (Pd1) are architected for Pd2Ga intermetallic nano -particles (NPs) using reactive metal-support interaction (RMSI). At elevated temperatures under hydrogen, in situ atomic-scale transmission electron microscopy directly visualizes the refacetting of Pd2Ga NPs from ener-getically favorable (013)/(020) facets to (011)/(002). Infrared spectroscopy and acetylene hydrogenation reaction complementarily confirm the evolution from consecutive Pd3 to Pd1 sites of Pd2Ga catalysts with the concurrent fingerprinting CO adsorption and featured reactivities. Through theoretical calculations and modeling, we reveal that the restructured Pd2Ga surface results from the preferential arrangement of additionally reduced Ga atoms on the surface. Our work provides previously unidentified mechanistic insight into temperature -pro-moted RMSI and possible solutions to control and rearrange the surface atoms of supported intermetallic catalyst.

Automated summary

This study achieves atom-by-atom control of the Pd2Ga intermetallic nano-particles (NPs) surface using reactive metal-support interaction (RMSI) and reveals the mechanism of surface restructuring. It provides possible solutions for controlling and rearranging the surface atoms of supported intermetallic catalysts.