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Optimizing product selectivity and conversion efficiency are primary goals in catalysis. However, efficiency and selectivity are often mutually antagonistic, so that high selectivity is accompanied by low efficiency and vice versa. Also, just increasing the temperature is very unlikely to change the reaction pathway. Here, by constructing hierarchical plasmonic nanoreactors, we show that nanoconfined thermal fields and energetic electrons, a combination of attributes that coexist almost uniquely in plasmonic nanostructures, can overcome the antagonism by regulating selectivity and promoting conversion rate concurrently. For propylene partial oxidation, they drive chemical reactions by not only regulating parallel reaction pathways to selectively produce acrolein but also reducing consecutive process to inhibit the overoxidation to CO2, resulting in valuable products different from thermal catalysis. This suggests a strategy to rationally use plasmonic nanostructures to optimize chemical processes, thereby achieving high yield with high selectivity at lower temperature under visible light illumination.

Plasmon-mediated chemical reactions (PMCRs) constitute a vibrant research field, advancing such goals as using sunlight to convert abundant precursors such as CO2 and water to useful fuels and chemicals. A key question in this burgeoning field which has not, as yet, been fully resolved, relates to the precise mechanism through which the energy absorbed through plasmonic excitation, ultimately drives such reactions. Among the multiple processes proposed, two have risen to the forefront: plasmon-increased temperature and generation of energetic charge carriers. However, it is still a great challenge to confidently separate these two effects and quantify their relative contribution to chemical reactions. Here, we describe a strategy based on the construction of a plasmonic electrode coupled with photoelectrochemistry, to quantitatively disentangle increased temperature from energetic charge carriers effects. A clear separation of the two effects facilitates the rational design of plasmonic nanostructures for efficient photochemical applications and solar energy utilization.

Defect passivation using additives has been demonstrated to be an effective approach to improve the efficiency and stability of perovskite devices. However, understanding the interactions and bonding state between additives and the film surface at the molecular level has been a long-standing challenge, due to the trace concentration of additives and the surface heterogeneity of perovskite films. Herein, by employing a non-destructive and label-free infrared nanospectroscopy technique, we achieved the experimental observations of inhomogeneously distributed additives on the surface of a hybrid organic–inorganic perovskite film, with spatial resolution down to 10 nm. For the first time, the association between the octylphosphonic acid (OPA) molecule and FA0.9MA0.05Cs0.05PbI3 film has been revealed at the molecular level. Chemical nanoimaging revealed that OPA additives were chiefly filled at the edges of the perovskite grain boundaries. With a higher spatial resolution of chemical nanoimaging, the OPA additive molecules were detected at the sub-grain boundary showing distinct cascade distribution characteristics. The analysis of the effect of OPA on the environmental stability of the perovskite proves a comprehensive passivation effect on the surface defect and the decomposition of organic components in perovskite thin films. Our work demonstrates an efficient approach for chemical nanoimaging of perovskites and provides a new spectroscopic insight into the modulation of additives on perovskites. [ABSTRACT FROM AUTHOR]

Due to the superior catalytic activity and efficient utilization of noble metals, nanocatalysts are extensively used in the modern industrial production of chemicals. The surface structures of these materials are significantly influenced by reactive adsorbates, leading to dynamic behavior under experimental conditions. The dynamic nature poses significant challenges in studying the structure–activity relations of catalysts. Herein, we unveil an anomalous entropic effect on catalysis via surface pre‐melting of nanoclusters through machine learning accelerated molecular dynamics and free energy calculation. We find that due to the pre‐melting of shell atoms, there exists a non‐linear variation in the catalytic activity of the nanoclusters with temperature. Consequently, two notable changes in catalyst activity occur at the respective temperatures of melting for the shell and core atoms. We further study the nanoclusters with surface point defects, i.e. vacancy and ad‐atom, and observe significant decrease in the surface melting temperatures of the nanoclusters, enabling the reaction to take place under more favorable and milder conditions. These findings not only provide novel insights into dynamic catalysis of nanoclusters but also offer new understanding of the role of point defects in catalytic processes. [ABSTRACT FROM AUTHOR]

Heterogeneous Catalysis. In their Communication (e202405379), Jun Cheng et al. use machine learning molecular dynamics to demonstrate anomalous entropic effect on catalysis via surface pre‐melting of nanoclusters...By Fu‐Qiang Gong; Yun‐Pei Liu; Ye Wang; Weinan E; Zhong‐Qun Tian and Jun ChengReported by Author; Author; Author; Author; Author; Author [Extracted from the article]