Recent advances towards increasing the Pt utilization efficiency for hydrogen evolution reaction: a review

The development of clean and sustainable energy sources is vital to address energy and environmental challenges. The generation of green hydrogen using efficient hydrogen evolution electrocatalysts is one of the promising approaches towards this goal. Among various HER electrocatalysts studied to date, Pt remains one of the most active catalysts which shows superior HER performance. However, its high cost due to scarcity impedes its potential large-scale commercialization at low cost. Therefore, increasing the Pt utilization efficiency without hampering its catalytic activity is the prime goal. In this review we will discuss recent progress made in increasing Pt utilization efficiency. The review starts by summarizing the basic mechanism and fundamentals of the HER. Then, in the next three sections recent progress made towards increasing Pt utilization efficiency by forming Pt alloys, heterostructures and single-atom Pt catalysts is discussed in detail. In the last section we discuss the role of pH and supporting cations in altering the HER rate on the surface of Pt catalysts. This research topic has not been much discussed in reviews and various mechanisms have been proposed for its basis, which are also presented. We hope that this review will help researchers better understand the recent advances made in improving Pt utilization efficiency. Pt, an ideal HER catalyst, is costly, hindering its use in wide-scale applications. Here, we discuss how advances to Pt alloys, heterostructures, and SACs improve Pt atomic utilization for HER, and how spectator ions and pH affect performance.