Emerging Heterogeneous Supports for Efficient Electrocatalysis

Abstract

HER), CO 2 reduction reaction (CO 2 RR), nitrogen reduction reaction (NRR), and so forth, which are all basic reactions in energy storage and conversion. [9][10][11][12] Electrocatalysts are the key component in determining reaction efficiency and energy utilization. Unfortunately, present catalysts perform unsatisfactorily in terms of activity, stability, selectivity, and preparation cost, which still cannot meet the practical needs and hinder their further application and development. [13][14][15] Many important conversion devices (such as proton exchange membrane electrolyzer) rely on precious metals such as Pt, Pd, Ir, and Ru, however, the high prices obstruct their large-scale applications. [16,17] To solve these bottlenecks, exploiting new electrocatalysts with high activity, good stability, high selectivity, and low cost is the solution to satisfy the requirements of modern industry.Loading catalysts on suitable supports has long been recognized as an appealing alternative strategy to save cost for the merit of high atom utilization. The substrate can not only enhance the overall conductivity but also ensure good stability and uniform dispersion of metal catalysts. [18,19] Simultaneously, the excellent dispersion ability of supports makes the obtained catalysts expose more surface/interface to allow catalytic reaction take place effectively. For instance, platinum nanoparticles dispersed on nanocarbon (i.e., Pt/C) have been employed as the commercial electrocatalysts for ORR and HER, which show excellent catalytic properties. [20,21] The success of their commercial application lies in the fact that the carbon support can avoid the aggregation of Pt nano particles and reduce platinum amount in reactions. The newly developed catalytic reactions put forward new requirements for supported catalysts that carbon-based materials cannot meet. For instance, in the strongly acidic or strongly oxidative environment during OER, carbon is not stable and will be oxidized or participate in the reactions. [22,23] In this aspect, noncarbon supports such as metal oxides, carbides, and nitrides, exhibit natural advantages thanks to their excellent durability in harsh environments as well as the strong electronic interaction between catalysts and supports. [24,25] In addition, some robust catalysts, including 2D materials-supported catalysts, singleatom catalysts, and self-supported catalysts, have been sprung up like mushrooms due to their unique structures, high activity, and good stability. [26][27][28][29] The vigorous development of supports has greatly enriched the design concept of catalysts.Many supported metal catalysts have been designed to achieve high catalytic efficiency toward various important electrochemical reactions such as OER, NRR, CO 2 RR, and Electrocatalysis plays a fundamental role in many fields, such as metallurgy, medicine, chemical industry, and energy conversion. Anchoring active electrocatalysts with controllable loading and uniform dispersion onto suitable supports has become an attractive topic...

Cu-Metal Organic Framework Derived Multilevel Hierarchy (Cu/CuxO@NC) as a Bifunctional Electrode for High-Performance Supercapacitors and Oxygen Evolution Reaction

“…Therefore, it illustrates that specific surface area increases with the increase in carbonization temperature; this leads to an increase in the carbon content. , The carbon-supported metal oxides shorten the electrolyte ions and diffusion path and allow for sufficient interaction between the active materials and the electrolyte ions . The earlier research demonstrates that nitrogen might improve the electrical conductivity and capacitive behavior of nanosheet-like carbon materials, leading to superior performance for supercapacitors and electrocatalytic applications. − …”

Mo modified Co3O4 nanosheets array by a rapid quenching strategy for efficient oxygen evolution electrocatalysis

“…Our self-supported Mo-Co 3 O 4 electrode avoids the use of expensive polymer binders to fix active material to the substrate. This work provides a valuable strategy to modify the electronic structure and OER catalytic performance of TMO, which obtains better OER activation (Wang et al, 2019;Li et al, 2018b;Yang J. et al, 2018;Zheng et al, 2018;Yu et al, 2019;Liu et al, 2020;Fan et al, 2022).…”

“…To accomplish modification for improving electrocatalytic performance, some feasible methods were raised such as solvothermal, precipitation, molten salt, and magnetron sputtering (Zhu et al, 2019;Xu H. et al, 2020;Zhang et al, 2020;Fan et al, 2022), which either lead to inevitable agglomeration and nucleation growth or cost too much for mass production (Yang et al, 2021). It is pivotal to develop a succinct and low-cost strategy to maintain the uniformity of microstructure.…”

Meso‐substituted Metalloporphyrin‐based Composites for Electrocatalytic Oxygen Reduction Reactions

“…[131] Heterogeneous molecular catalysts with a high electric conductive and porous support have the potential to significantly improve interfacial electron transport efficiency and catalytic activity since the strong interaction with electrodes. [132] Due to the large specific surface areas as well as the intense connection in the constructed structure, heterogeneous catalysis typically has the high atom-utilization efficiency. [133] In addition, heterogeneous catalysts have the advantages of facile separation from the reaction system once finished and can be recovered.…”

“…It is believed that homogeneous catalysis of porphyrins can be of high activity due to the direct connection and dense active sites, but it faces several parasitic disadvantages in practical applications, for instance, poor electrical conductivity, weak interactions with electrodes, low molecular utilization, difficulty to recycle, etc [131] . Heterogeneous molecular catalysts with a high electric conductive and porous support have the potential to significantly improve interfacial electron transport efficiency and catalytic activity since the strong interaction with electrodes [132] . Due to the large specific surface areas as well as the intense connection in the constructed structure, heterogeneous catalysis typically has the high atom‐utilization efficiency [133] .…”