Lewis-Base Coordination Enables Highly Dispersed Pt Cocatalyst on Pyrene-Based MOFs for Enhanced Photocatalytic Hydrogen Evolution.

Rationally optimizing the coordination structures of Pt-based cocatalysts to concurrently achieve enhanced charge separation/transfer and lowered reaction energy barriers is significant for photocatalysis. Herein, we engineered the coordination of Pt cocatalyst on pyrene-based metal-organic frameworks (MOFs) through grafting different Lewis-base groups. The softness of the introduced groups directly determines their affinity for Pt precursors, allowing for precise tailoring of the electronic metal-support interactions (EMSI) of Pt and MOFs, which leads to the distinct Pt coordination structures. These structural features accelerate charge separation/transfer by an established internal electric field and lower catalytic energy barriers enabled by the oxidized Pt surface, leading to significantly enhanced photocatalytic activity. Specifically, the -SH-functionalized MOF (Pt/NU-M), featuring strong EMSI, achieves atomic dispersion of Pt-O/S coordination and delivers a superior hydrogen evolution rate of 5.68 mmol gcat -1 h-1 (405.71 mmol gpt -1 h-1) when using ascorbic acid as a sacrificial agent upon full-spectrum light irradiation, which is about 16 times higher than that of the Pt/NU control and surpasses many reported MOF-based materials. Notably, the catalyst maintains exceptional stability over 20 h of continuous operation. This work highlights Lewis-base coordination for tailoring active sites and optimizing EMSI, providing new insights for rational catalyst design and related energy applications.