Oxygen promoted hydrogen production from formaldehyde reforming with oxide-derived Cu nanowires at room temperature

This work demonstrates a two-step method to produce oxide-derived Cu nanowires on Cu mesh surface to offer a monolithic catalyst that outstandingly improves the hydrogen production from reforming formaldehyde and water under ambient conditions.Our results not only reveal that the special oxidederived nanostructure can significantly improve the formaldehyde reforming performance of Cu,but also display that the hydrogen production has a linear relationship with oxygen pressure.Specially,a maximum of 36 times increment in hydrogen generation rate is observed than that without oxygen during the reaction.Density functional theory calculations show that the formaldehyde molecule is adsorbed on Cu surface only when the adsorbed oxygen is in adjacency,and hydrogen release process is the ratedetermining step.This work highlights that the activity of deliberately synthesized catalyst can further be promoted by dynamic chemical modulation of surface states during working.

Spin-Enhanced C-C Coupling in CO_(2)Electroreduction with Oxide-Derived Copper

Electrocatalytic reduction of carbon dioxide(CO_(2))to multicarbon(C2+)products involves intricate multiple protons and electron transfer of C-C coupling,which is dictated by not only the intrinsic reactivity but also the spin states of electrons in the catalyst.Here,we observe spin-enhanced CO_(2)reduction(CO_(2)RR)electrocatalytic activity on an oxidederived copper(OD-Cu)catalyst due to the existence of a specific Cu*site that carried the magnetic moments.Due to the correlation of magnetic and catalytic properties in OD-Cu,the current density through the OD-Cu electrode increases by nearly 10%at 350 mT.The field strength and angle dependence of such magnetic field effect(MFE),together with the time-resolved measurements proved that it originated from the alignment of magnetic moments on Cu*sites.The MFE on the electrocatalytic process enabled an enhancement(up to 15%)of the CO_(2)RR Faradaic efficiency using the OD-Cu catalyst.Importantly,the enhancement was attributed to the spinantiparallel alignment of electrons to promote C-C coupling on asymmetric Cu*-Cu sites;consequently,the optimal bias was reduced by∼0.2 V under the magnetic field for C2 products with Faradaic efficiency>30%and selectivity>75%.Our work uncovers a new paradigmfor spin-enhanced catalysis applicable to a broad range of chemical reactions involving spin singlet products.

Recent progress on copper catalysts with different surface states for CO_(2)electroreduction

The electrochemical carbon dioxide reduction reaction(eCO_(2)RR),which converts CO_(2)into various hydrocarbons or alcohols,has been extensively researched because it promises a sustainable energy economy.However,only copper(Cu)can currently achieve stable and efficient hydrocarbon conversion in the eCO_(2)RR.Therefore,understanding the catalytic mechanisms and summarizing the research progress on synthesis strategies of Cu catalysts are essential for the eCO_(2)RR.This paper reviews Cu catalysts with different surface states of Cu catalysts:oxide-derived Cu,Cu nanoparticles,Cu single atoms,and Cu nanoclusters.It then reviews the development and progress of different Cu-catalyst preparation methods in recent years,focusing on the activity and selectivity of materials.Besides revealing the tendencies of catalytic selection and deep reactive mechanisms of Cu catalysts with four different surface states,this review can guide the subsequent construction of catalysts and provides an understanding of catalytic mechanisms.