Review and Perspective on Transition Metal Electrocatalysts Toward Carbon-Neutral Energy

Abstract

Decarbonizing the chemical industry and achieving carbon-neutral energy is paramount to the sustainability of the human species on earth. Electrocatalysis using transition metalbased catalysts plays a major role in achieving this task. In this work, we present an overview on the application of transition metal-based catalysts in electrocatalytic reactions. We particularly focus on the advancement of the hydrogen evolution reaction (HER), oxygen evolution reaction (OER), oxygen reduction reaction (ORR), nitrogen reduction reaction (NRR), and carbon dioxide reduction reaction (CO 2 RR) using transition metal electrocatalysts. We also aim to highlight the major achievements in these fields and the limitations in their large-scale industrial applications. Different transition metal catalysts are discussed, from 3-dimensional to 1-to 0-dimensional structures. We place special attention to the emerging transition metal catalysts such as 2dimensional carbide and nitride MXenes and single atom catalysts. Lastly, we offer recommendation for future research directions for the aforementioned electrocatalysis fields using transition metal electrocatalysts. This work will ultimately help both existing and incoming researchers in these fields in providing the state-of-the-art research findings and identifying the major challenges that must be addressed in order to attain carbon-neutral energy.

A Review on the Application of In-Situ Raman Spectroelectrochemistry to Understand the Mechanisms of Hydrogen Evolution Reaction

“…The most studied and optimized MXene is Ti 3 C 2 T x , which has gained a large amount of attention due to its high performance in various systems and ease of modification. Ti 3 C 2 T x MXenes have been employed as supports for typical working HER electrocatalysts to optimize the overall electronic structure . For example, charge transfer from the – O– termination groups of the Ti 3 C 2 T x MXene has been utilized to optimize the electronic structure of Pt atoms or NPs loaded on the MXene support .…”

Review and Perspectives of Carbon-Supported Platinum-Based Catalysts for Proton Exchange Membrane Fuel Cells

“…In 1993, Ballard Power Systems of Canada launched the world’s first electric vehicle powered by the PEMFC. In 2015, the Toyota Mirai fuel cell vehicle , was launched in Japan as the world’s first generation of mass-produced hydrogen fuel cell vehicles, causing a significant boost to the adoption of PEMFCs. Currently, with the decreasing cost and increasing durability of PEMFCs, an increasing number of automotive brands are vigorously developing PEMFC technology to bring electric vehicles to market.…”

“…William Grove 4 used sulfuric acid solution as the electrolyte in 1839 and formed a fuel cell by contacting the platinum (Pt)-plated electrode with hydrogen and oxygen. This work was the first to discover fuel cells, which were called gasvolt batteries at that time, and explain the principle of In 2015, the Toyota Mirai fuel cell vehicle 5,6 was launched in Japan as the world's first generation of massproduced hydrogen fuel cell vehicles, causing a significant boost to the adoption of PEMFCs. Currently, with the decreasing cost and increasing durability of PEMFCs, an increasing number of automotive brands are vigorously developing PEMFC technology to bring electric vehicles to market.…”

Electrodeposited Multimetal Alloyed NiMoCo on Ni Mesh for Efficient Alkaline Hydrogen Evolution Reaction

“…Currently, transition-metal-based electrocatalysts − show great promise in alkaline water splitting because of their excellent hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) activities. , Among the reported transition-metal-based electrocatalysts, NiMo-based HER electrodes have attracted attention because of their excellent HER properties. , However, they face practical stability problems of Mo leaching during electrolysis, especially under industrial conditions. , The introduction of a guest element into the NiMo binary electrocatalysts would change the electronic state to improve its electrocatalytic performance or inhibit the dissolution of Mo to increase material stability. , For example, Toghraei et al prepared Ni–Mo–P coatings by one-step electrodeposition on nickel foam (NF) with better catalytic activity than Ni–Mo/NF electrodes, requiring an overpotential of only 63 mV to obtain a current density of 10 mA cm –2 for HER in alkaline media. The performance enhancement was ascribed to the mutual synergistic interaction between Ni, Mo, and P elements, and the introduction of P could change the original electronic structure in the NiMo alloy.…”

“…7−9 Currently, transition-metal-based electrocatalysts 10−13 show great promise in alkaline water splitting because of their excellent hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) activities. 14,15 Among the reported transition-metal-based electrocatalysts, NiMo-based HER electrodes have attracted attention because of their excellent HER properties. 16,17 However, they face practical stability problems of Mo leaching during electrolysis, especially under industrial conditions.…”