Controlling the surface chemistry towards unsaturated carbon-carbon bonds over non-oxide transition metal ceramics: Trends in adsorption and distortion energies and adsorbate “activation”

Abstract

Controlling the surface chemistry of catalysts towards unsaturated carbon-carbon bonds is vital to achieving many contemporary chemical transformations. Transition metal (TM) ceramics are promising materials that exhibit lower and tunable surface reactivity towards C=C bonds. Herein, we have employed an analysis of the adsorption of benzene over a large suite of TM ceramic and pure metal surfaces to benchmark a large selection of materials to isolate trends. Results showed a wide range of surface reactivity as a function of the constituent elements, surface composition, TM-to-p-element ratio, surface ensemble size, electronic structure, etc. The 1st row TM ceramics exhibited lower surface reactivity and more stable surface composition than the 2nd/3rd TM ceramics suggesting that orbital-size match could be a simple marker for predicting general surface chemistry and surface composition stability in TM solid compounds. The TM-to-p-element ratio also generally dictated metal-like or markedly-modified reactivity of the constituent elements at the ceramic surface. Electronic analysis further quantified the correlation between the density and type of electronic states near the Fermi level and the reactivity of surface-lattice elements. Structural and energetic analysis of the adsorbed benzene indicated the activation of the adsorbate could be better quantified beyond simple adsorption energy.