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Electrocatalytic CO2 reduction reaction (CO2RR) for CH4 production presents a promising strategy to address carbon neutrality, and the incorporation of a second metal has been proven effective in enhancing catalyst performance. Nevertheless, there remains limited comprehension regarding the fundamental factors responsible for the improved performance. Herein, the critical role of Pd in electrocatalytic CO2 reduction to CH4 on Cu-based catalysts has been revealed at a molecular level using in situ surface-enhanced Raman spectroscopy (SERS). A "borrowing" SERS strategy has been developed by depositing Cu–Pd overlayers on plasmonic Au nanoparticles to achieve the in situ monitoring of the dynamic change of the intermediate during CO2RR. Electrochemical tests demonstrate that Pd incorporation significantly enhances selectivity toward CH4 production, and the Faradaic efficiency (FE) of CH4 is more than two times higher than that for the catalysts without Pd. The key intermediates, including *CO2−, *CO, and *OH, have been directly identified under CO2RR conditions, and their evolution with the electrochemical environments has been determined. It is found that Pd incorporation promotes the activation of both CO2 and H2O molecules and accelerates the formation of abundant active *CO and hydrogen species, thus enhancing the CH4 selectivity. This work offers fundamental insights into the understanding of the molecular mechanism of CO2RR and opens up possibilities for designing more efficient electrocatalysts. [ABSTRACT FROM AUTHOR]

Understanding water activation and reaction at metal-oxide interfaces is of significant importance. However, it remains a great challenge due to the weak signal of surface-active species and the difficulties associated with in situ detection methods. Herein, the water-gas shift reaction mechanism at the Pd–CeO2 interfaces has been systematically studied by using the "borrowing" surface-enhanced Raman spectroscopy (SERS) strategy through the fabrication of Au@CeO2–Pd core–shell satellite structures. Through the combination of in situ SERS and online mass spectrometry, real-time monitoring of surface intermediate species and reaction products is achieved simultaneously. It is found that CO adsorbed on Pd can either react with the oxygen species formed via water dissociation (the associative mechanism) or the lattice oxygen in CeO2 (the redox mechanism), with the former having a higher activity. This work provides an effective approach for the in situ study of interfacial catalysis and explains the important role of the Pd–CeO2 interfaces in the water-gas shift reaction at a molecular level. [ABSTRACT FROM AUTHOR]

Raman spectroscopy is a popular technology for material identification, but it encounters difficulties when distinguishing components with closely related substances by intuition and experience. The distinction of fats and oils is a typical example, which is significant in the food industry. In this work, the Raman spectroscopy and deep learning algorithm are combined to analyze closely related animal fats (lard, butter, mutton fat and chicken fat) and vegetable oils (soybean oil and peanut oil) in a dataset. A deep neural network founded on the VGG architecture with attention mechanism is developed, reaching an accuracy of 100% for fats and oils classification. By combining Raman spectroscopy with deep learning, this research provides a potent technique for tackling the identification of similar substances. In this work, the Raman spectroscopy and deep learning algorithm are combined to analyze closely related animal fats (lard fat, butter fat, mutton fat and chicken fat) and vegetable oils (soybean oil and peanut oil) in a dataset. A deep neural network founded on the VGG architecture with attention mechanism is developed, reaching an accuracy of 100% for fats and oils classification. [ABSTRACT FROM AUTHOR]

The gas release within Li‐ion batteries, particularly during cycling and storage, can result in rapid performance degradation and potential safety hazards. However, this area has not garnered sufficient attention until now, primarily because the gassing information collected by typical OEMS/DEMS is quite limited and even inaccurate. Herein, for the first time, a state‐of‐the‐art on‐line GC‐BID/MS to full‐dimensionally analyze the gassing behavior within both lab‐scale coin‐type cell (in situ mode) and industry‐scale pouch‐type cell (operando mode) is originally designed/constructed. Not limited to common permanent gases (e.g. H2, CO, etc.) detected by online GC‐BID, but also complicated/various (semi‐)volatile products are identified/quantified by online GC‐MS. Based on the real‐time evolution information of water, alcohols, aldehydes, ethers, esters, and hydrocarbons, the decomposition mechanisms of electrolyte on both graphite anode and/or LCO cathode sides is further supplemented/perfected. Moreover, at the level of the device, series derivative/crosstalk reactions induced by trapped/accumulated gaseous species are unveiled in practical pouch‐cell. [ABSTRACT FROM AUTHOR]

Highlights: In situ Raman spectroscopy study of the cation regulation for interfacial water on Au@Pd core–shell nanoparticle surface during hydrogen evolution reaction process. Direct spectral evidence reveals new strategies to optimize the structure of interfacial water by the adjusting of radius and valence of the cation in the electrolyte. The optimized structure of interfacial water will improve the charge transfer efficiency between the water and electrode increasing the performance of the hydrogen evolution reaction. Interfacial water molecules are the most important participants in the hydrogen evolution reaction (HER). Hence, understanding the behavior and role that interfacial water plays will ultimately reveal the HER mechanism. Unfortunately, investigating interfacial water is extremely challenging owing to the interference caused by bulk water molecules and complexity of the interfacial environment. Here, the behaviors of interfacial water in different cationic electrolytes on Pd surfaces were investigated by the electrochemistry, in situ core–shell nanostructure enhanced Raman spectroscopy and theoretical simulation techniques. Direct spectral evidence reveals a red shift in the frequency and a decrease in the intensity of interfacial water as the potential is shifted in the positively direction. When comparing the different cation electrolyte systems at a given potential, the frequency of the interfacial water peak increases in the specified order: Li+ < Na+ < K+ < Ca2+ < Sr2+. The structure of interfacial water was optimized by adjusting the radius, valence, and concentration of cation to form the two-H down structure. This unique interfacial water structure will improve the charge transfer efficiency between the water and electrode further enhancing the HER performance. Therefore, local cation tuning strategies can be used to improve the HER performance by optimizing the interfacial water structure. [ABSTRACT FROM AUTHOR]

Pt/C is one of the most favorable catalysts with high catalytic activity used in the oxygen reduction reaction (ORR). However, the synthesis of Pt/C with superior durability is still a significant challenge. Here, we introduced a simple technique to fabricate a Pt/N-C catalyst, having ultrasmall Pt nanocrystals encapsulated inside a nitrogen-doped carbon support, which is derived by the UiO-66-NH2 (MOF) using an impregnation technique, followed by a pyrolysis process. This Pt/N-C displays ORR activity and durability in alkaline solution with a half-wave potential of 0.90 V (vs RHE), limited diffusion current density of 5.5 mA cm–2, and only 5 mV deterioration in half-wave potential after testing 20,000 cyclic voltammetry (CV) cycles. In addition, it also shows good performance in acidic solution. In addition, Zn–air batteries (ZABs) assembled using the Pt/N-C air electrode display a high specific capacity of 825 mAh g–1, a high peak power density of 372 mW cm–2, and 208 h long cycle life. This offers an innovative approach for developing noble metal-based catalysts with unusual activity, stability, and a promising future for applications in metal–air batteries and fuel cells. [ABSTRACT FROM AUTHOR]