Self-assembly of a Rh(I) complex on Au(111) surfaces and its electrocatalytic activity toward the hydrogen evolution reaction

Selective Catalytic Chemistry at Rhodium(II) Nodes in Bimetallic Metal-Organic Frameworks

We report the first study of a gas-phase reaction catalyzed by highly dispersed sites at the metal nodes of a crystalline metal-organic framework (MOF). Specifically, CuRhBTC (BTC^3- =benzenetricarboxylate) exhibited hydrogenation activity, while other isostructural monometallic and bimetallic MOFs did not. Our multi-technique characterization identifies the oxidation state of Rh in CuRhBTC as +2, which is a Rh oxidation state that has not previously been observed for crystalline MOF metal nodes. These Rh²⁺ sites are active for the catalytic hydrogenation of propylene to propane at room temperature, and the MOF structure stabilizes the Rh²⁺ oxidation state under reaction conditions. Density functional theory calculations suggest a mechanism in which hydrogen dissociation and propylene adsorption occur at the Rh²⁺ sites. The ability to tailor the geometry and ensemble size of the metal nodes in MOFs allows for unprecedented control of the active sites and could lead to significant advances in rational catalyst design.

Graphene/nano-porous silicon and graphene/bimetallic silicon nanostructures (Pt–M, M: Pd, Ru, Rh), efficient electrocatalysts for the hydrogen evolution reaction

In this work nano-porous silicon flour (Nano-PSiF) was synthesized first and then there was an investigation into its electrocatalytic activity for the electrochemical hydrogen evolution reaction (HER).