Superfast Synthesis of Densely Packed and Ultrafine Pt-Lanthanide@KB via Solvent-Free Microwave as Efficient Hydrogen Evolution Electrocatalysts

At present, it is still a great challenge to synthesize refractory Pt-based electrocatalysts with excellent active specific surface area, specific activity, and stability by a simple method. Here, a superfast and solvent-free microwave strategy is reported to synthesize refractory ultrafine (approximate to 3 nm) Pt-lanthanide@Ketjen Black (PtM@KB, M = La, Gd, Tb, Er, Tm, and Yb) alloy with densely packed as efficient hydrogen evolution electrocatalysts in a domestic microwave oven for the first time. The optimized Pt61La39@KB delivers excellent hydrogen evolution reaction (HER) activity with a low overpotential of 38 mV (10 mA cm(-2)) and a high TOF value of 44.13 s(-1) (100 mV) in 0.5 m H2SO4, and performs well in 1.0 m KOH. This method can also be used to grow catalysts on carbon cloth (CC) directly. PtLa@CC shows an overpotential of 99 mV (1000 mA cm(-2)) in 0.5 m H2SO4 and can maintain activity after 500 h. Theoretical calculations reveal the enhanced stability and activity owing to the higher vacancy formation energy of Pt atoms and the optimized value of Delta G(H*). Solvent-free microwave strategy constitutes a significant insight into the development of refractory electrocatalyst with ultrafine size and highly dense, which can also work well at high current densities.

Automated summary

A novel solvent-free microwave strategy is reported for synthesizing refractory Pt-based electrocatalysts with excellent activity and stability in hydrogen evolution reaction. The method also allows direct growth of catalysts on carbon cloth, showing promising potential applications.