Atomic ruthenium stabilized on vacancy-rich boron nitride for selective hydrogenation of esters

Abstract

Constructing and taming metal–support interaction of atoms and/or clusters has emerged as a promising protocol to maximize the catalytic performance of noble metal-based materials. Here, we report atomic ruthenium (Ru) with the oxidized state immobilized on defect-rich hexagonal boron nitride (d-BN) nanosheets and the essential interfacial electronic effect on Ru deduced from B- and N-vacancies for superior selective hydrogenation of esters. Experimental results indicate that strong electronic interplay exists between vacancies and atomic Ru species. Unlike defect-free commercial hexagonal BN (h-BN), d-BN can highly stabilize the active Ru species in atomic scale with oxidation state, and the obtained Ru/d-BN significantly increases the catalytic activity and durability. Specifically, the turnover frequency of Ru/d-BN is more than one order of magnitude higher than that of the conventional optimized Ag/SiO2 catalyst for the selective hydrogenation of dimethyl oxalate to methyl glycol. Systematic characterizations show that the Ru on B- and N-vacancies, and the defective BN serves as electron acceptor. The findings demonstrate the overall electronic effect on the electron-rich feature of Ru on d-BN, such that the electronic metal–support interactions cause the Ru species to favor the adsorption and selective scission of C–O bonds in esters, revealing a highly efficient hydrogenation catalysis.