Strain Engineering in Electrocatalysts: Fundamentals, Progress, and Perspectives

Abstract

sive utilization of fossil fuels. The design and development of efficient, economic, and sustainable strategies to convert clean energy (e.g., solar energy, wind energy, and hydropower energy) is thus of great significance. Among various available strategies, electrochemical energy conversion technologies have been attracted extreme attention. They mainly include (photo)electrochemical reduction of atmosphere-rich and greenhouse gas-carbon dioxideinto high value-added chemicals or liquid fuels under mild reaction conditions, electrosynthesis of NH 3 with low energy consumption to substitute the Haber method, electrochemical overall water splitting, and different kinds of fuel cells. By use of these electrochemical energy conversion technologies, it is believed that both the issues of energy shortage and environmental pollution are promising to be solved, eventually creating a globalized system with a sustainable energy circle for our society in the future (Figure 1). [1][2][3][4][5][6][7] To achieve efficient electrochemical conversion technologies, high-performance electrochemical conversion platforms need to be initialized, where electrocatalysts are frequently required. An electrocatalyst actually plays a vital role in the determination and further improvement of reaction rate, efficiency, and selectivity of different electrochemical transformations. In terms of its catalytic performance, the most crucial factors are generally considered as the amount of its active sites, the intrinsic activity of each active site, and the total efficiency of these active sites. [8] It is well-known that the amount of active sites of an electrocatalyst and its electrocatalytic efficiency can be increased through enlarging the surface area of an electrocatalyst, for example by means of synthesizing a nanostructured catalyst (e.g., nanosheets, [9] nanowires, [10] nanopores, [11][12][13] and coreshell structures [14,15] ). Meanwhile, the intrinsic activity of each catalytic site basically follows the Sabatier principle, [16][17][18][19][20] which is closely related to the ability of an electrocatalyst to weaken or strengthen the binding energies with reactants, reaction intermediates, and/or products. For example, when the free energy of hydrogen adsorption (ΔG H ) on the active sites of an electrocatalyst remains at a moderate strength, this catalyst exhibits the highest catalytic activity toward hydrogen evolution reaction (HER). In contrast, too strong or too weak ΔG H on the active sites of an electrocatalyst precludes the HER. [21][22][23] Among numerous electrocatalysts, multiple metal components based electrocatalysts have been extensively utilized in Strain engineering of nanomaterials, namely, designing, tuning, or controlling surface strains of nanomaterials is an effective strategy to achieve outstanding performance in different nanomaterials for their various applications. This article summarizes recent progress and achievements in the development of strain-rich electrocatalysts (SREs) and their applications in the fi...

Electronic structure engineering for electrochemical water oxidation

“…As the electrochemical performance of a material directly correlates to its electronic structure, it can, therefore, be effectively tuned by strain engineering. Various methods have been used to generate strain in the catalysts including epitaxial growth of thin films 161,162 , formation of bimetallic nanoparticles 163 and crystal morphology engineering 164 . Through first-principles calculations, Yildiz and co-workers 165 showed a planar strain effect on the oxygen-vacancy formation and oxygen adsorption in LaCo 3 .…”

“…Various methods have been used to generate strain in the catalysts including epitaxial growth of thin films, 161,162 formation of bimetallic nanoparticles 163 and crystal morphology engineering. 164…”

“…Various methods have been used to generate strain in the catalysts including epitaxial growth of thin lms, 161,162 formation of bimetallic nanoparticles 163 and crystal morphology engineering. 164 Through rst-principles calculations, Yildiz and coworkers 165 showed a planar strain effect on the oxygen-vacancy formation and oxygen adsorption in LaCo 3 . The adsorption of oxygen molecules transitioned from chemisorption to physisorption at high strain.…”

Strain‐Induced Structure Evolution of Multimetallic Nanoplates

“…In general, the PtAgPb/C nanoplates display the superior specific and mass activity compared to commercial Pt/C due to the unique 2D structure, [3,8] abundant twinned defects, [5] and low-coordinate step atoms. [1,8,27] The Tafel slope value of PtAgPb-IV/C is less than that of the Pt/C catalyst (Figure S29, Supporting Information) proving that the PtAgPb-IV/C catalyst has improved kinetic behavior and higher current density than that of Pt/C. Moreover, the electron-transfer number (n) during ORR was calculated by the well-known Koutecky-Levich (K-L) equation (Figure S30, Supporting Information) in the potential range of 0.40-0.70 V vs RHE.…”

Predicting Surface Strain Effects on Adsorption Energy with Graph Neural Networks

“…Improvements in the precision of epitaxial material growth and core-shell nanoparticle synthesis by bottom-up and top-down approaches has enabled finer control over material structure for a given composition. 61 Using experimentally measured structural data as can help distinguish different reaction mechanisms by enabling relative comparisons of different intermediates and reaction pathways on a particular surface using one model. We anticipate that flexible model architectures such as GNNs will improve catalyst design by bridging the gap between accurate but expensive first-principles simulations and experimentally relevant high-dimensional spaces such as strain.…”