Anion Modulation of Pt‐Group Metals and Electrocatalysis Applications

Abstract

Pt-group metal (PGM) electrocatalysts with unique electronic structures and irreplaceable comprehensive properties play crucial roles in electrocatalysis. Anion engineering can create a series of PGM compounds (such as RuP 2 , IrP 2 , PtP 2 , RuB 2 , Ru 2 B 3 , RuS 2 , etc.) that provide a promising prospect for improving the electrocatalytic performance and use of Ptgroup noble metals. This review seeks the electrochemical activity origin of anion-modulated PGM compounds, and systematically analyzes and summarizes their synthetic strategies and energy-relevant applications in electrocatalysis. Orientation towards the sustainable development of nonfossil resources has stimulated a blossoming interest in the design of advanced electrocatalysts for clean energy conversion. The anion-modulated strategy for Pt-group metals (PGMs) by means of anion engineering possesses high flexibility to regulate the electronic structure, providing a promising prospect for constructing electrocatalysts with superior activity and stability to satisfy a future green electrochemical energy conversion system. Based on the previous work of our group and others, this review summarizes the up-to-date progress on anion-modulated PGM compounds (such as RuP 2 , IrP 2 , PtP 2 , RuB 2 , Ru 2 B 3 , RuS 2 , etc.) in energy-related electrocatalysis from the origin of their activity and synthetic strategies to electrochemical applications including hydrogen evolution reaction (HER), oxygen evolution reaction (OER), oxygen reduction reaction (ORR), hydrogen oxidation reaction (HOR), N 2 reduction reaction (NRR), and CO 2 reduction reaction (CO 2 RR). At the end, the key problems, countermeasures and future development orientations of anionmodulated PGM compounds toward electrocatalytic applications are proposed.

Duetting electronic structure modulation of Ru atoms in RuSe2@NC enables more moderate H* adsorption and water dissociation for hydrogen evolution reaction

“…The Sabatier principle indicates that moderate appropriate Gibbs free energy of hydrogen bonding (DG *H ) is crucial for HER catalysts. 33,34 Fig. 1a shows *H adsorption accompanied with the rst proton/electron transfer of RuSe 2 and RuSe 2 @NC, indicating pure RuSe 2 with a higher energy barrier of 0.54 eV can only serve as a weak *H adsorption catalyst for HER.…”

Mapping Hydrogen Evolution Activity Trends of Intermetallic Pt-Group Silicides

“…1,3 Thus, the huge challenge to the commercial viability of PGMs prompts an endless stream of modification strategies aimed at reducing the dosage while further improving the catalytic activity. 5 Currently, available modification strategies of PGMs mainly include microstructure regulation, 6,7 supporting engineering, 8,9 and transition-metal doping and alloying. 10,11 By comparison, as an emerging modification strategy, the anion (B, P, N, S, Se, and Te) engineering toward PGMs possesses unique features and advantages.…”

“…10,11 By comparison, as an emerging modification strategy, the anion (B, P, N, S, Se, and Te) engineering toward PGMs possesses unique features and advantages. 5,12 First, the formed intermetallic compounds have fixed crystal structures, facilitating the identification of real active sites to explore new catalytic mechanisms. 13,14 Moreover, the introduced atoms improve the coordination environment of PGMs through surface electronic effects, interstitial electronic effects, lattice strain effects, and orbital hybrid effects, and so forth, thereby optimizing the electronic structure and surface adsorption.…”

“…Hydrogen evolution reaction (HER) is one of the most important reactions in electrochemistry, in which the hydrogen adsorption process on catalysts is the key step of the reaction. , The Sabatier principle indicates that the ideal HER catalyst possesses moderate Gibbs free energy of hydrogen bonding (Δ G H* ≈ 0). , At present, Pt-group metals (PGMs: Pt, Ru, Pd, Os, Ir, and Rh) and their compounds are at the top region of the hydrogen evolution volcano trend curve with suitable Δ G H* , which are still difficult to be replaced by nonprecious metal-based catalysts. , Thus, the huge challenge to the commercial viability of PGMs prompts an endless stream of modification strategies aimed at reducing the dosage while further improving the catalytic activity …”

“…Currently, available modification strategies of PGMs mainly include microstructure regulation, , supporting engineering, , and transition-metal doping and alloying. , By comparison, as an emerging modification strategy, the anion (B, P, N, S, Se, and Te) engineering toward PGMs possesses unique features and advantages. , First, the formed intermetallic compounds have fixed crystal structures, facilitating the identification of real active sites to explore new catalytic mechanisms. , Moreover, the introduced atoms improve the coordination environment of PGMs through surface electronic effects, interstitial electronic effects, lattice strain effects, and orbital hybrid effects, and so forth, thereby optimizing the electronic structure and surface adsorption. , Besides, the difference in electronegativity induces a strong host–guest electron interaction, further awakening the unexcited metal active sites and heightening the catalytic activity . Therefore, the modulation strategy of non-metal and metalloid anions has an unlimited potential in improving the utilization efficiency of PGMs.…”