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 field of electrochemical energy conversion technologies. It starts from the definition of lattice strains, followed by the classification of lattice strains where the mechanisms of strain formation and the reported methods to regulate related strains are elaborated. The SRE characterization techniques are overviewed, focusing deeply on the clarification of the strain‐property relationship of these SREs. Their applications for different electrocatalytic reactions are further highlighted, including the hydrogen evolution reaction, oxygen reduction reaction, oxygen evolution reaction, alcohol oxidation reaction, electrochemical carbon dioxide reduction reaction, and nitrogen reduction reaction. Related reaction mechanisms of the SREs are interpreted after taking catalytic performance, as well as the relationship between the SRE properties and their strains into account. The challenges and future opportunities to regulate SREs are finally outlined and discussed together with their potential applications in different fields.

Hydrogen peroxide (H₂O₂) is a high-demand organic chemical reagent and has been widely used in various modern industrial applications. Currently, the prominent method for the preparation of H₂O₂ is the anthraquinone oxidation. Unfortunately, it is not conducive to economic and sustainable development since it is a complex process and involves unfriendly environment and potential hazards. In this context, numerous approaches have been developed to synthesize H₂O₂. Among them, photo/electro-catalytic ones are considered as two of the most promising manners for on-site synthesis of H₂O₂. These alternatives are sustainable in that only water or O₂ is required. Namely, water oxidation (WOR) or oxygen reduction (ORR) reactions can be further coupled with clean and sustainable energy. For photo/electro-catalytic reactions for H₂O₂ generation, the design of the catalysts is extremely important and has been extensively conducted with an aim to obtain ultimate catalytic performance. This article overviews the basic principles of WOR and ORR, followed by the summary of recent progresses and achievements on the design and performance of various photo/electro-catalysts for H₂O₂ generation. The related mechanisms for these approaches are highlighted from theoretical and experimental aspects. Scientific challenges and opportunities of engineering photo/electro-catalysts for H₂O₂ generation are also outlined and discussed.

Direct alcohol fuel cells (DAFCs) utilize alcohol electro‐oxidation reactions (AORs) to provide electricity, where catalysts with optimal electronic structures are required to accelerate sluggish AORs. Herein, an electrocatalyst with an Au‐nanorod core and a PdPt‐alloy shell is designed. Its electronic structures are modulated through epitaxial growth of a PdPt‐alloy shell on the Au‐nanorod core, which exhibits a tensional strain effect and atomic steps. Three key problems of AORs are solved with this catalyst, including poor adsorption of alcohols on the catalyst, CO poisoning of the catalyst, and a high free energy barrier for the AORs. Taking methanol electro‐oxidation reaction (MOR) as an example, this catalyst shows 9.4 times higher mass activity than the market‐available Pt/C catalyst. Theoretic simulations prove that this catalyst has a low free energy barrier for the MOR, and strong adsorption of methanol but weaker adsorption of carbonaceous intermediates. The reasons behind this are the stretched geometric structure of the PdPt (100)‐alloy shell and the optimized electronic structure of catalytic sites on the catalyst surface. Meanwhile, efficient electro‐oxidation of ethanol, ethylene glycol, and glycerol is realized. This work paves the way to design and synthesize universal and efficient AOR catalysts for the construction of high‐performance DAFCs.

Ethanol is preferred to be oxidized into CO₂ for the construction of a high‐performance direct ethanol fuel cell since this complete ethanol oxidation reaction (EOR) transfers 12 electrons. However, this EOR is sluggish and has the low activity as well as poor selectivity. To promote such a favorable EOR, more exactly the cleavage selectivity of CC bonds in ethanol, phosphorus‐doped silver‐core‐and‐Pd‐shell catalysts (denoted as Ag@PdP) are designed and synthesized. In the alkaline media, a Ag@Pd₂P_0.2 catalyst is superior toward EOR into CO₂. It exhibits seven times higher mass activity and six times higher selectivity than the benchmark Pd/C catalyst. As confirmed by means of density functional theory calculation and in situ Fourier‐transform infrared spectroscopy, such high performance stems from an increased adsorption energy of OH radicals on the Pd active sites. Meanwhile, the tensile strain effect of a core–shell structure of this Ag@Pd₂P_0.2 catalyst favors the formation of adsorbed CH₃CO intermediate, the key species for the enhanced C–C cleavage into CO₂, instead of acetate. The proposed way to design and synthesize such high‐performance EOR catalysts will explore the practical applications of direct alkaline ethanol fuel cells.

TiO₂nanotube arrays coated with a carbon film by MLD exhibit excellent capability for PEC water splitting with an optimized carbon-film thickness.