Disentangling interfacial and alloying effects in bimetallic catalysts via surface organometallic chemistry on metal

Shahar Dery, Chemistry, Bar-Ilan University, Ramat-Gan, Israel (shahar.dery@biu.ac.il)
Wei Zhou, Chemistry, Eth Zurich, Zurich, Switzerland
Chengbo Yao, Chemistry, Eth Zurich, Zurich, Switzerland
Christophe Copéret, Chemistry, Eth Zurich, Zurich, Switzerland


Promotional effects are ubiquitous across catalytic processes involving supported nanoparticles, where additional elements, so-called promoters, significantly enhance the catalytic performances (activity, selectivity and stability) of nanoparticles. However, the inherent complexity of these catalysts makes it difficult to understand the effect of promoters at the molecular level. Surface organometallic chemistry (SOMC) is a powerful tool to decouple the complexity of catalysts by constructing better-defined model systems. To overcome this challenge, we developed a new methodology termed “SOMC on metal” that enables us to specifically study the role of the group 6 elements as promoters for the reverse water-gas shift (RWGS) reaction. Specifically, our work focuses on the two SOMC approaches to construct Pt bimetallic catalysts with or without Cr interfacial Lewis acid sites for the low-temperature RWGS reaction. Notably, we show that a catalyst containing exclusively PtCr alloys, PtCr@SiO₂, displays a substantial promotional effect in catalytic activity compared to monometallic Pt@SiO₂, while having additional Cr-interfacial sites (PtCr-Cr_int@SiO₂) further improves the catalytic activity. In situ spectroscopic results reveal that PtCr alloy facilitates a redox reaction pathway, whereas an additional formate-mediated pathway takes place at the interface between PtCr alloy and Cr(III) Lewis acid sites. These findings highlight that both PtCr alloy and Cr-interfacial sites contribute to enhancing the RWGS activity. The insights gained from these well-defined systems provide guidelines for the rational design of more active catalysts.

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Short Biography of Presenting Author

Shahar Dery

Assistant Professor, Bar-Ilan University

Shahar Dery earned his B.Sc., M.Sc., and Ph.D. in Chemistry from the Hebrew University of Jerusalem, where he worked with Prof. Elad Gross on nanospectroscopic visualization of catalytic reactions on single nanoparticles, work that earned the HUJI Nano Prize, the Azrieli Fellowship, and the ICS Uri Golik Prize. As a Swiss Government Excellence Postdoctoral Fellow at ETH Zurich with Prof. Christophe Copéret, he combined surface organometallic chemistry and solid-state NMR to study N-heterocyclic carbene (NHC)-metal single sites, uncovering distinct NMR signatures of NHC–gold bonding. He also received an ETH Career Seed Grant to advance operando spectroscopy for heterogeneous catalysis. In 2025, Shahar joined Bar-Ilan University as an Assistant Professor, where his lab explores the electronic and structural properties of catalytic surfaces. He is a recipient of the Alon Fellowship and a Genesis–ISF research grant.