Design principles for hydrogen evolution reaction catalyst materials

Abstract

Design and synthesis of active, stable and cost-effective materials for efficient hydrogen production (hydrogen evolution reaction, HER) is of paramount importance for the successful deployment of hydrogen-based alternative energy technologies. The HER, seemingly one of the simplest electrochemical reactions, has served for decades to bridge the gap between fundamental electrocatalysis and practical catalyst design. However, there are still many open questions that need to be answered before it would be possible to claim that design principles of catalyst materials are fully developed for the efficient hydrogen production. In this review, by summarizing key results for the HER on well-characterized electrochemical interfaces in acidic and alkaline media, we have broadened our understanding of the HER in the whole range of pH by considering three main parameters: the nature of the proton donor (H 3 O + in acid and H 2 O in alkaline), the energy of adsorption of H ad and OH ad , and the presence of spectator species. Simply by considering these three parameters we show that great deal has already been learned and new trends are beginning to emerge, giving some predictive ability with respect to the nature of electrochemical interface and electrocatalytic activity of the HER.

Synergistic Nanotubular Copper‐Doped Nickel Catalysts for Hydrogen Evolution Reactions

“…To gain insights into the HER kinetics, Tafel plots (Figure b) derived from the polarization curves were determined to elucidate the elementary steps involved in the HER processes (see details in Experimental Section). HER mechanism in alkaline media generally involves two routes: Volmer–Tafel process or Volmer–Heyrovsky pathway, each with its characteristic Tafel slope . As seen in Figure b, the as‐prepared Ni(Cu)/NF exhibits a Tafel slope as low as 33.3 mV dec −1 , which is much smaller than that of NF (123.6 mV dec −1 ), Ni/NF (108.1 mV dec −1 ), and NiCu/NF (96.3 mV dec −1 ), and close to Pt/C/NF (25.1 mV dec −1 ).…”

Mechanistic Insights into Light‐Activated Catalysis for Water Oxidation

“…Although oxygen can be considered a useless by‐product in artificial photosynthesis, water oxidation provides the reducing equivalents necessary for the synthesis of fuels, typically by reduction of protons to hydrogen, or by reduction of carbon dioxide to carbon monoxide, formic acid, methanol or methane . Efforts in this field have been focused on the development of new and efficient catalysts, but also on the mechanistic investigation for the identification of reaction rates and intermediates involved in breaking and formation of bonds, in particular the most challenging one related to the formation of the oxygen–oxygen bond , …”

Co-generation of hydrogen and power/current pulses from supercapacitive MFCs using novel HER iron-based catalysts

“…Similar to the oxygen reduction reaction (ORR), catalysts are generally used to significantly decrease the overpotentials and accelerate the reaction in which hydrogen is evolved. In acidic and alkaline conditions, Ir and Pt are known to be the best catalysts for HER [14], [15]. Platinum is the most used and reported catalyst for HER in MEC [16], [17], but the high cost compared to the hydrogen produced and the possibility of catalyst poisoning due to sulfur pollutants in wastewater does not make it the best candidate for HER in MECs for large applications [18].…”