Multi-metallic catalysts have been found to significantly increase catalytic efficiency, compared to the monometallic counterparts. This enhancement can be attributed to various alloying effects: i) the existence of unique mixed-metal surface sites [the so called ensemble effect]; ii) the modification of electronic state due to metal-metal interactions [the so called ligand (electronic) effect]; and iii) strain caused by lattice mismatch between the alloy components [the so called strain effect]. However, mechanisms underlying the alloying effect still remain unclear owing to the difficulty of direct characterization. Computational approaches, particularly the prediction using first-principles density functional theory, can be a powerful and flexible alternative for unraveling the role of alloying effects in catalysis since those can give us quantitative insights into the catalytic systems. In this talk, I will present the underlying principles that govern the selective hydrogen production via formic acid decomposition occurring on Pd-based multi-metallic catalysts [M(or Pd3M)-Pd core shell] using the first-principles calculations[1-4]. In particular, the impact of the strain and ligand effects on the catalysis of HCOOH decomposition is systematically analyzed by decoupling such alloying effects. Our theoretical calculation offers the fundamental mechanism of HCOOH decomposition on bimetallic Pd catalysts and also provides physical and chemical intuition for the next generation bimetallic catalyst.

Elucidating the role of heteronuclear interactions in boosting H2 production from HCOOH decomposition on bimetallic Pd-M catalysts from first-principles

254th National Meeting (2017)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.