Rational design of MoS2-based catalysts toward lignin hydrodeoxygenation: Interplay of structure, catalysis, and stability

The MoS2-based materials are a vital class of heterogeneous catalysts for the hydrodeoxygenation of lignin and its model compounds to produce value-added chemicals especially because of their unique selectivity to aromatics. The rational design of MoS2-based catalyst greatly depends on the comprehensive understanding of its structure-activity relationship. However, an intensive summary and critical analysis are still scarce to date. In this review, we attempt to provide an in-depth understanding of the interplay of structure, catalysis, and stability of MoS2-based catalysts for lignin hydrodeoxygenation. The recognition of intrinsic active sites on MoS2 structure was firstly discussed, followed by the illustration of MoS2-catalyzed hydrodeoxygenation structural models. Afterward, based on the studies on the MoS2-catalyzed lignin model compounds hydrodeoxygenation, the current active site modification strategies including structural modification of monometallic MoS2 catalysts and collaborative modification were summarized and emphatically discussed, which aims to elucidate the structure-activity relationship at the atomic-level. The deactivation mechanism and stabilization strategies were also illustrated to provide instructive suggestion for the rational design of efficient and stable MoS2-based catalysts. Finally, the real lignin depolymerization over MoS2-based catalysts was summarized to point out the advantages and difficulties. This review attempts to highlight the remaining challenges and provide some perspectives for the future development of MoS2-based catalysts for lignin hydrodeoxygenation.