Opportunities of MXenes in Heterogeneous Catalysis. V2C as Aerobic Oxidation Catalyst.

Abstract

MXenes are 2D nanomaterials having alternating sheets of one atom-thick early transition metal layer and one atom-thick C or N layer. The external surface contains termination groups, whose nature depends on the etching agent used in the preparation procedure from the MAX phase. The present concept proposes that, due to their composition, the metal-surface termination groups make MXenes particularly suited as heterogeneous catalysts for some reactions. T Afterpresentingthe concept, we have selected V2C Mxene asexample to illustrate its catalytic activity showing how the catalytic performance varies when the surface groups are modified. As test reaction we selected the aerobic oxidation of indane to the corresponding indanol/indanone mixture using molecular oxygen as terminal oxidizing reagent. Two previously reported procedures to modify the surface groups, namely surface dehydroxylation by thermal treatment under diluted hydrogen flow and surface oxidation with ammonium monoperoxy sulfate to convert some surface groups into oxo groups were used, observing in both cases a decrease in the catalytic activity of V2C. Based on this, VIII/IV-OH are proposed as catalytic centers in this aerobic oxidation. Overall, the present concept shows the merits of MXenes in heterogeneous catalysis, based on their chemical composition and the surface functionality.