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Electrochemical conversion of CO2 and water to valuable chemicals and fuels is one of the promising alternatives to replace fossil fuel-based processes in realizing a carbon-neutral cycle. For practical application of such technologies, suppressing hydrogen evolution reaction and facilitating the activation of stable CO2 molecules still remain major challenges. Furthermore, high production selectivity toward high-value chemicals such as ethylene, ethanol, and even n-propanol is also not easy task to achieve. To settle these challenges, deeper understanding on underlying basis of reactions such as how intermediate binding affinities can be engineered at catalyst surfaces need to be discussed. In this review, we briefly outline recent strategies to modulate the binding energies of key intermediates for CO2 reduction reactions, based on theoretical insights from density functional theory calculation studies. In addition, important design principles of catalysts and electrolytes are also provided, which would contribute to the development of highly active catalysts for CO2 electroreduction.

Direct formic acid fuel cells (DFAFCs) stand out for portable electronic devices owing to their ease of handling, abundant fuel availability, and high theoretical open circuit potential. However, the practical application of DFAFCs is hindered by the unsatisfactory performance of electrocatalysts for the sluggish anodic formic acid oxidation reaction (FAOR). Palladium (Pd) based nanomaterials have shown promise for FAOR due to their highly selective reaction mechanism, but maintaining high electrocatalytic durability remains challenging. In this study, a novel Pd‐based electrocatalyst (UiO‐Pd‐E) is reported with exceptional durability and activity for FAOR, which can be attributed to the Pd nanoparticles encapsulated within a carbon framework where concurrent chemical alloying of Pd and Zr occurs. Further, the UiO‐Pd‐E demonstrates noteworthy multifunctionality in various electrochemical reactions including electrocatalytic ethanol oxidation reaction (EOR) and oxygen reduction reaction (ORR) in addition to the FAOR, highlighting its practical potentials. [ABSTRACT FROM AUTHOR]

The surging demand for sustainable energy has spurred intensive research into electrochemical conversion devices such as fuel cells, water splitting, and metal‐air batteries. The performance of oxygen electrocatalysts significantly impacts overall electrochemical efficiency. Recently, spinel oxides (AB2O4) have emerged as promising candidates; however, the scarcity of prior studies underscores the need for a thorough and comprehensive exploration. This study presents a computational framework that integrates machine learning and density functional theory (DFT) calculations for the systematic screening of 1240 spinel oxides. The data scarcity is addressed while enhancing prediction accuracy. Selected candidates are identified to outperform the benchmarking perovskite oxide. Additionally, their potential as mixed ionic and electronic conductors with a 3D network of ion diffusion pathways is highlighted. To further enhance the understanding and prediction of stability, catalytic activity, and reaction mechanisms, a new undemanding descriptor is introduced: the covalency indicator. This study offers a design principle for the development of high‐performance spinel oxide oxygen electrocatalysts. [ABSTRACT FROM AUTHOR]

Sodium superionic conductor (NASICON)‐type cathode materials are considered promising candidates for high‐performance sodium‐ion batteries (SIBs) because of the abundance and low cost of raw materials. However, NASICON‐type cathodes suffer from low capacities. This limitation can be addressed through the activation of sodium‐excess phases, which can enhance capacities up to theoretical values. Thus, this paper proposes the use of transition metal (TM)‐substituted Na3V2(PO4)2F3 (NVPF) to induce sodium‐excess phases. To identify suitable doping elements, an inverse design approach is developed, combining machine learning prediction and density functional theory (DFT) calculations. Graph‐based neural networks are used to predict two crucial properties, i. e., the structural stability and voltage level. Results indicate that the use of TM‐substituted NVPF materials leads to about 150 % capacity enhancement with reduced time and resource requirements compared with the direct design approach. Furthermore, DFT calculations confirm improvements in cyclability, electronic conductivity, and chemical stability. The proposed approach is expected to accelerate the discovery of superior materials for battery electrodes. [ABSTRACT FROM AUTHOR]

Electrochemical water splitting offers an advancing approach to producing highly pure hydrogen and oxygen, motivated by the prevalence of a low‐carbon economy and the goal of a sustainable future. The customized modulation of electronic structures enables the electrocatalyst to directionally promote hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), which is a promising shortcut to overall water splitting (OWS). Herein, 3D homologous WSeS/CoSeS heterojunction nanoarrays (WSeS/CoSeS NAs) and W‐doped CoSeS nanoarrays (W‐CoSeS NAs) are investigated. Abundant heterointerfaces within WSeS/CoSeS NAs facilitate HER kinetics, boosting mass diffusivity, and increasing carrier separation and transfer process. High‐valence W6+ doping into CoSeS prevents phase separation and stabilizes Co sites by charge offset effect, leading to enhanced OER. Consequently, the WSeS/CoSeS NAs and W‐CoSeS NAs reach 10 mA cm−2 at an overpotential of 43.8 and 233.3 mV in 1.0 m KOH electrolyte for HER and OER, respectively. Moreover, when asymmetrically engaged as an electrolyzer, this configuration exhibits extraordinary electrocatalytic performances (cell voltage of 1.51 V at 10 mA cm−2) with satisfying stability and mechanical robustness (over 1000 h at 1000 mA cm−2). The modulation and manufacture of reaction‐property‐oriented materials are experimentally and theoretically validated potential, illuminating the light of inspiration for multiple applications. [ABSTRACT FROM AUTHOR]