ELECTRON AND STRUCTURAL FORMATION CHARACTERISTICS OF METAL NANOCLUSTER-CARRIER INTERFACIAL PHASE BOUNDARIES IN MOLYBDENUM CARBIDE SURFACES

Abstract

The research investigates the catalytic performance of cubic δ-MoC and orthorhombic β-Mo2C (001) surfaces in CO2 hydrogenation and water-gas shift (WGS) reactions using Density Func-tional Theory (DFT) calculations. The study reveals that the metal-to-carbon stoichiometry plays a fundamental role in determining activity, selectivity, and stability. While the β-Mo2C phase demon-strates high reactivity by spontaneously dissociating CO2 at room temperature, it suffers from rapid deactivation due to surface poisoning (oxycarbide formation) and low selectivity toward methanol as it favors methane production. In contrast, the δ-MoC surface provides a more stable and selective platform where direct CO2 dissociation is avoided. The addition of small Cu and Au nanoclusters significantly enhances the catalytic efficiency. Specifically, the Cu/δ-MoC system acts as a bifunc-tional catalyst, facilitating CO2 activation through a redox mechanism, which increases methanol yield by 8-11 times compared to industrial Cu/ZnO models. These findings provide a theoretical foundation for developing cost-effective catalysts for sustainable fuel production and CO2 utilization.