Modulating Hydrogen Adsorption by Unconventional p-d Orbital Hybridization over Porous High-entropy Alloy Metallene for Efficient Electrosynthesis of Nylon-6 Precursor.

Renewable electricity driven electrosynthesis of cyclohexanone oxime (C6H11NO) from cyclohexanone (C6H10O) and nitrogen oxide (NOx) is a promising alternative to traditional environment-unfriendly industrial technologies for green synthesis of C6H11NO. Precisely controlling the reaction pathway of the C6H10O/NOx-involved electrochemical reductive coupling reaction is crucial for selectively producing C6H11NO, which is yet still challenging. Herein, we report a porous high-entropy alloy PdCuAgBiIn metallene (HEA-PdCuAgBiInene) to boost the electrosynthesis of C6H11NO from C6H10O and nitrite, achieving a high Faradaic efficiency (47.6%) and almost 100% yield under ambient conditions. In situ Fourier transform infrared spectroscopy and theoretical calculations demonstrate that unconventional orbital hybridization between d-block metals and p-block metals could regulate the local electronic structure of active sites and induce electron localization of electron-rich Pd sites, which tunes the active hydrogen supply and facilitates the generation and enrichment of key intermediates NH2OH* and C6H10O*, and efficiently promotes their C-N coupling to selectively produce C6H11NO.

Selective CO2 Electroreduction to Formate on Polypyrrole-Modified Oxygen Vacancy-Rich Bi2 O3 Nanosheet Precatalysts by Local Microenvironment Modulation.

Challenges remain in the development of highly efficient catalysts for selective electrochemical transformation of carbon dioxide (CO2 ) to high-valued hydrocarbons. In this study, oxygen vacancy-rich Bi2 O3 nanosheets coated with polypyrrole (Bi2 O3 @PPy NSs) are designed and synthesized, as precatalysts for selective electrocatalytic CO2 reduction to formate. Systematic material characterization demonstrated that Bi2 O3 @PPy precatalyst can evolve intoBi2 O2 CO3 @PPy nanosheets with rich oxygen vacancies (Bi2 O2 CO3 @PPy NSs) via electrolyte-mediated conversion and function as the real active catalyst for CO2 reduction reaction electrocatalysis. Coating catalyst with a PPy shell can modulate the interfacial microenvironment of active sites, which work in coordination with rich oxygen vacancies in Bi2 O2 CO3 and efficiently mediate directional selective CO2 reduction toward formate formation. With the fine-tuning of interfacial microenvironment, the optimized Bi2 O3 @PPy-2 NSs derived Bi2 O2 CO3 @PPy-2 NSs exhibit a maximum Faradaic efficiency of 95.8% at -0.8 V (versus. reversible hydrogen electrode) for formate production. This work might shed some light on designing advanced catalysts toward selective electrocatalytic CO2 reduction through local microenvironment engineering.

Engineering Under-Coordinated Active Sites with Tailored Chemical Microenvironments over Mosaic Bismuth Nanosheets for Selective CO2 Electroreduction to Formate.

Selective electrochemical reduction of CO2 into fuels or chemical feedstocks is a promising avenue to achieve carbon-neutral goal, but its development is severely limited by the lack of highly efficient electrocatalysts. Herein, cation-exchange strategy is combined with electrochemical self-reconstruction strategy to successfully develop diethylenetriamine-functionalized mosaic Bi nanosheets (mBi-DETA NSs) for selective electrocatalytic CO2 reduction to formate, delivering a superior formate Faradaic efficiency of 96.87% at a low potential of -0.8 VRHE . Mosaic nanosheet morphology of Bi can sufficiently expose the under-coordinated Bi active sites and promote the activation of CO2 molecules to form the OCHO- * intermediate. Moreover, in situ attenuated total reflectance infrared spectra further corroborate that surface chemical microenvironment modulation of mosaic Bi nanosheets via DETA functionalization can improve CO2 adsorption on the catalyst surface and stabilize the key intermediate (OCHO- *) due to the presence of amine groups, thus facilitate the CO2 -to-HCOO- reaction kinetics and promote formate formation.