Effects of Inorganic Salt Types and Concentrations on the Catalytic Performance of Molybdenum Disulfide in Naphthalene Hydrogenation

Abstract

This study investigates the influence of inorganic salt types and concentrations on the structural characteristics and catalytic performance of MoS2 in the hydrogenation of naphthalene. MoS2 catalysts modified with various inorganic salts at different concentrations were synthesized via a hydrothermal method. The catalysts were characterized using XRD, Raman, SEM, EDS, TEM, Mapping, BET and XPS. The catalytic performance of the synthesized materials was evaluated in the hydrogenation of naphthalene. The results indicate that different inorganic salts and their concentrations exert distinct effects on the structure, sulphur vacancies and catalytic performance of MoS2. KCl modification promotes the formation of the 1T phase of MoS2, with lower concentrations yielding a more pronounced effect. MgCl2 modification primarily expands the interlayer spacing of MoS2 via intercalation, with the most significant expansion observed at a concentration of 0.01 mol/L. In contrast, the adsorption of Al3+ on the MoS2 surface promotes the enlargement of nanosheet dimensions and specific surface area, significantly increases the concentration of sulphur vacancies, and synergistically enhances both the yield and selectivity of tetralin. The optimal naphthalene conversion of 79.84%, representing a 9.41% improvement over unmodified MoS2, was achieved with 0.005M KCl modification. The highest tetralin yield of 71.19%, a 2.92% increase compared to the unmodified catalyst, was obtained with 0.01M AlCl3 modification. This study elucidates the controllable modulation mechanism of MoS2 structure via inorganic salt modification, offering insights for the design of high-performance hydrogenation catalysts.