Surface Engineering of Carbon-Supported Platinum as a Route to Electrocatalysts with Superior Durability and Activity for PEMFC Cathodes

Hydrogen fuel cells are regarded as a promising new carbon mitigation strategy to realize carbon neutrality. The exploitation of robust and efficient cathode catalysts is thus vital to the commercialization of proton exchange membrane fuel cells (PEMFCs). Herein, we demonstrate a facile and scalable surface engineering route to achieve superior durability and high activity of a Pt-based material as a PEMFC cathode catalyst through a controllable liquid-phase reduction approach. The proposed surface engineering strategy by modifying Pt/C reduces the oxygen content on the carbon support and also decreases the surface defects on Pt nanoparticles (NPs), which effectively alleviate the corrosion of carbon and inhibit the detachment, agglomeration, and growth of Pt NPs. The resulting catalyst exhibits superior durability after a 10,000 potential cycling test in an acid electrolyte─outperforming commercial Pt/C. Moreover, the catalyst also demonstrates an improved oxygen reduction reaction (ORR) activity in comparison to commercial Pt/C by virtue of the high content of metallic Pt and the weakened Pt-OH bonding that releases more Pt active sites for ORR catalysis. Most importantly, the developed catalyst shows outstanding PEMFC performance and excellent long-term durability over 50 h of a constant-current test and 100 h of a load-cycling operation. This effective route provides a new avenue for exploiting robust Pt-based catalysts with superior activity in practical applications of PEMFCs.

Metal-free reduction of unsaturated carbonyls, quinones, and pyridinium salts with tetrahydroxydiboron/water

A series of unsaturated carbonyls, quinones, and pyridinium salts have been effectively reduced to the corresponding saturated carbonyls, dihydroxybenzenes, and hydropyridines in moderate to high yields with tetrahydroxydiboron/water as a mild, convenient, and metal-free reduction system. Deuterium-labeling experiments have revealed this protocol to be an exclusive transfer hydrogenation process from water.