Heterogeneous MoS2 catalysts for regioselective olefin hydrocarboxylation using formic acid

Hydrocarboxylation of olefins is an important route to carboxylic acids and their derivatives, but conventional processes rely on toxic carbon monoxide and harsh reaction conditions. Formic acid has emerged as an attractive alternative C1 source because it can be produced directly from CO 2 electroreduction; however, selective activation of formic acid toward hydrocarboxylation remains challenging, particularly in heterogeneous systems. Herein, we report a noble-metal-free heterogeneous MoS 2 -based catalytic system that enables regioselective hydrocarboxylation of olefins using formic acid under mild conditions, addressing a longstanding challenge in heterogeneous formic-acid-mediated C-C bond formation. Through systematic catalyst design, clear structure-activity relationships were established. The optimized Cu/O-HSA-MoS 2 catalyst affords γ-butyrolactone from allyl alcohol in up to 55.9 % yield with > 99 % selectivity, exhibits good substrate scope with anti-Markovnikov selectivity, and maintains stable performance over multiple recycling cycles. Spectroscopic analyses, including XPS, Raman spectroscopy, and in situ X-ray absorption spectroscopy, suggest that oxygen incorporation generates edge-associated acid-base functionalities on MoS 2 that facilitate selective formic acid activation, while Cu species act as promoters that enhance reaction efficiency. Overall, this work establishes a sustainable, CO-free heterogeneous platform for C-C bond formation directly linked to CO 2 valorization chemistry.