Zn-Modified MoS2 Catalyst for Efficient CO2 Hydrogenation to CH3OH

Abstract

Abstract Hydrogenation of carbon dioxide (CO2) to methanol (CH3OH) using hydrogen produced from renewable energy sources is a promising pathway for carbon recycling and energy storage. Molybdenum disulfide (MoS2), with its typical layered structure, holds significant industrial potential for low-temperature CO2 hydrogenation to CH3OH. The in-plane sulfur vacancies of MoS2 are considered active sites for their catalytic activity on hydrogenation of CO2 to CH3OH, while the edge sulfur vacancies lead to over-hydrogenation to produce methane (CH4). In this work, a simple pyrolysis method was employed to modify MoS2-based catalysts with Zn, which helps to steer the dominant product from methane to methanol. Under the conditions of 220 °C, 5 MPa, and a gas hourly space velocity (GHSV) of 9000 mL gcat–1 h–1, the ZnS–MoS2 catalyst achieved a CO2 conversion of 9.7% with a CH3OH selectivity of 81.9%, yielding a methanol space-time yield (STY) of 6.4 mmol gcat–1 h–1. By optimizing the space velocity, the STY was elevated to 17.4 mmol gcat–1 h–1. This represents a performance among the best of reported MoS2-based systems under equivalent environments.