Halide anion adsorption on transition metals can improve the performance of electrochemical CO2 reduction reaction (CO2RR), while the specific reaction mechanisms governing selective CO2RR pathways remain unclear. In this study, we demonstrate for the first time the distinct pathways for gaseous (CO) and liquid products (formate and ethanol) on the well‐defined Ag‐Cu nanostructures with controlled chlorination, respectively. We show that CO2 conversion to CO on Ag/AgCl can be tuned by adjusting the thickness of AgCl layer, achieving a Faradaic efficiency (FE) near 100% over a broad potential range in a 0.5 M KHCO3 using flow cell. In contrast, the optimized Cl‐Ag/Cu system enables the conversion of CO2 into liquid products including formate and ethanol with a total FE nearing 100%, delivering high current density under similar conditions. In situ infrared experiments and theoretical calculations reveal that the lateral adsorbate of *OCHO intermediate facilitates the thermodynamics of both the CO pathway on Cl‐Ag(111) and the formate pathway on Cl‐Ag/Cu(111) by reducing Gibbs free energy barriers of each potential‐limit step. This work uncovers the role of chlorination in the tuning of C‐bound or O‐bound intermediates during CO2RR on Ag‐Cu catalysts, determining the reaction pathway under lateral adsorbate effects.
Demetalation caused by the electrochemical dissolution of metallic Fe atoms is a major challenge for the practical application of Fe─N─C catalysts. Herein, an efficient single metallic Mn active site is constructed to improve the strength of the Fe─N bond, inhibiting the demetalation effect of Fe─N─C. Mn acts as an electron donor inducing more delocalized electrons to reduce the oxidation state of Fe by increasing the electron density, thereby enhancing the Fe─N bond and inhibiting the electrochemical dissolution of Fe. The oxygen reduction reaction pathway for the dissociation of Fe─Mn dual sites can overcome the high energy barriers to direct O─O bond dissociation and modulate the electronic states of Fe─N
The judicious management of water and nitrogen (N) is pivotal for augmenting crop productivity and N use efficiency, while also mitigating environmental concerns. With the advent of the High−Farmland Construction Program in China, one−off irrigation has become feasible for most dryland fields, presenting a novel opportunity to explore the synergistic strategies of water and N management. This study delves into the impact of one−off alternate furrow irrigation (AFI) and topdressing N fertilizer (TN) on soil nitrate−N distribution, and N productivity—including plant N accumulation, translocation, and allocation, and grain yield, protein content, N use efficiency of winter wheat (Triticum aestivum L.) in 2018−2019 and 2019−2020. Experimental treatments administered at the jointing stage comprised of two irrigation methods—every (EFI) and alternative (AFI) furrow irrigation at 75 mm, and two topdressing N rates—0 (NTN) and 60 (TN) kg N ha −1 . Additionally, a conventional local farmer practice featuring no irrigation and no topdressing N (NINTN) was served as control. Compared to NINTN, EFINTN substantially increased aboveground N accumulation, grain yield, and protein yield, albeit with a reduction in grain protein content by 8.1%−10.6%. AFI, in turn, led to higher nitrate−N accumulation in the 60−160 cm soil depth at booting and anthesis, but diminished levels at maturity, resulting in a significant surge in N accumulation from anthesis to maturity and its contribution to grain, N fertilizer partial factor productivity (PFPN), and N uptake efficiency (NUPE), thereby promoting grain yield by 9.9% and preserving grain protein content. Likewise, TN enhanced soil nitrate−N at key growth stages, reflected in marked improvements in N accumulation both from booting to anthesis and from anthesis to maturity, as well as in grain yield, protein content, and protein yield. The combination of AFI and TN (AFITN) yielded the highest grain yield, protein content, with PFPN, NUPE, and N internal efficiency outstripping those of EFINTN, but not AFINTN. In essence, one−off AFI coupled with TN at the jointing stage is a promising strategy for optimizing soil nitrate−N and enhancing wheat N productivity in dryland where one−off irrigation is assured.
Halide anion adsorption on transition metals can improve the performance of electrochemical CO2 reduction reaction (CO2RR), while the specific reaction mechanisms governing selective CO2RR pathways remain unclear. In this study, we demonstrate for the first time the distinct pathways for gaseous (CO) and liquid products (formate and ethanol) on the well-defined Ag-Cu nanostructures with controlled chlorination, respectively. We show that CO2 conversion to CO on Ag/AgCl can be tuned by adjusting the thickness of AgCl layer, achieving a Faradaic efficiency (FE) near 100% over a broad potential range in a 0.5 M KHCO3 using flow cell. In contrast, the optimized Cl-Ag/Cu system enables the conversion of CO2 into liquid products including formate and ethanol with a total FE nearing 100%, delivering high current density under similar conditions. In situ infrared experiments and theoretical calculations reveal that the lateral adsorbate of *OCHO intermediate facilitates the thermodynamics of both the CO pathway on Cl-Ag(111) and the formate pathway on Cl-Ag/Cu(111) by reducing Gibbs free energy barriers of each potential-limit step. This work uncovers the role of chlorination in the tuning of C-bound or O-bound intermediates during CO2RR on Ag-Cu catalysts, determining the reaction pathway under lateral adsorbate effects.
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