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Current techno-economic evaluation manifests that the electrochemical CO 2 reduction reaction (eCO 2 RR) to CO is very promising considering its simple two-electron transfer process, minimum cost of electricity, and low separation cost. Herein, we report a Sn-modification strategy that can tune the local electronic structure of Cu with an appropriate valence. The as-prepared catalysts can alter the broad product distribution of Cu-based eCO 2 RR to predominantly generate CO. CO faradaic efficiency (FE) remained above 96% in the wide potential range of -0.5 to -0.9 V vs. the reversible hydrogen electrode (RHE) with CO partial current density up to 265 mA cm -2 . The catalyst also had remarkable stability. Operando experiments and density functional theory calculations demonstrated that the surface Cu δ + sites could be modulated and stabilized after introducing Sn. The Cu δ + sites with low positive valence were conducive to regulating the binding energy of intermediates and resulted in high CO selectivity and maintained the stability of the catalyst. Additionally, scaling up the catalyst into a membrane electrode assemble system (MEA) could achieve a high overall current of 1.3 A with exclusive and stable CO generation., Competing Interests: The authors declare no competing financial interests., (This journal is © The Royal Society of Chemistry.)

The electroreduction of CO 2 to CH 4 has attracted extensive attention. However, it is still a challenge to achieve high current density and faradaic efficiency (FE) for producing CH 4 because the reaction involves eight electrons and four protons. In this work, we designed Cu nanoparticles supported on N-doped carbon (Cu-np/NC). It was found that the catalyst exhibited outstanding performance for the electroreduction of CO 2 to CH 4 . The FE toward CH 4 could be as high as 73.4% with a high current density of 320 mA cm -2 . In addition, the mass activity could reach up to 6.4 A mg Cu -1 . Both experimental and theoretical calculations illustrated that the pyrrolic N in NC could accelerate the hydrogenation of *CO to the *CHO intermediate, resulting in high current density and excellent selectivity for CH 4 . This work conducted the first exploration of the effect of N-doped species in composites on the electrocatalytic performance of CO 2 reduction., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Powered by a renewable electricity source, electrochemical CO 2 reduction reaction is a promising solution to facilitate the carbon balance. However, it is still a challenge to achieve a desired product with commercial current density and high efficiency. Herein we designed quasi-square-shaped cadmium hydroxide nanocatalysts for CO 2 electroreduction to CO. It was discovered that the catalyst is very active and selective for the reaction. The current density could be as high as 200 mA cm -2 with a nearly 100% selectivity in a commonly used H-type cell using the ionic liquid-based electrolyte. In addition, the faradaic efficiency of CO could reach 90% at a very low overpotential of 100 mV. Density functional theory studies and control experiments reveal that the outstanding performance of the catalyst was attributed to its unique structure. It not only provides low Cd-O coordination, but also exposes high activity (002) facet, which requires lower energy for the formation of CO. Besides, the high concentration of CO can be achieved from the low concentration CO 2 via an adsorption-electrolysis device., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Electrocatalytic reduction of CO 2 into multicarbon (C 2+ ) products powered by renewable electricity offers one promising method for CO 2 utilization and promotes the storage of renewable energy under an ambient environment. However, there is still a dilemma in the manufacture of valuable C 2+ products between balancing selectivity and activity. In this work, cerium oxides were combined with CuO (CeO 2 /CuO) and showed an outstanding catalytic performance for C 2+ products. The faradaic efficiency of the C 2+ products could reach 75.2% with a current density of 1.21 A cm -2 . In situ experiments and density functional theory (DFT) calculations demonstrated that the interface between CeO 2 and Cu and the subsurface Cu 2 O coexisted in CeO 2 /CuO during CO 2 RR and two competing pathways for C-C coupling were promoted separately, of which hydrogenation of *CO to *CHO is energetically favoured. In addition, the introduction of CeO 2 also enhanced water activation, which could accelerate the formation rate of *CHO. Thus, the selectivity and activity for C 2+ products over CeO 2 /CuO can be improved simultaneously., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Oxide-derived copper (OD-Cu) has been discovered to be an effective catalyst for the electroreduction of CO 2 to C2+ products. The structure of OD-Cu and its surface species during the reaction process are interesting topics, which have not yet been clearly discussed. Herein, in situ surface-enhanced Raman spectroscopy (SERS), operando X-ray absorption spectroscopy (XAS), and 18 O isotope labeling experiments were employed to investigate the surface species and structures of OD-Cu catalysts during CO 2 electroreduction. It was found that the OD-Cu catalysts were reduced to metallic Cu(0) in the reaction. CuO x species existed on the catalyst surfaces during the CO 2 RR, which resulted from the adsorption of preliminary intermediates (such as *CO 2 and *OCO - ) on Cu instead of on the active sites of the catalyst. It was also found that abundant interfaces can be produced on OD-Cu, which can provide heterogeneous CO adsorption sites (strong binding sites and weak binding sites), leading to outstanding performance for obtaining C2+ products. The Faradaic efficiency (FE) for C2+ products reached as high as 83.8% with a current density of 341.5 mA cm -2 at -0.9 V vs. RHE., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Multi-shelled hollow structured materials featuring large void volumes and high specific surface areas are very promising for a variety of applications. However, controllable synthesis of multi-shelled hollow structured intermetallic compounds remains a formidable challenge due to the high annealing temperature commonly required for the formation of intermetallic phases. Here, a topological self-template strategy was developed to solve this problem. Using this strategy, we prepared well-defined multi-shelled intermetallic Ni 3 Ga hollow microspheres (Ni 3 Ga-MIHMs) as disclosed by the HAADF-STEM, HRTEM, and EDS characterizations, and the BET specific surface areas of them measured as much as 153.4 m 2 g -1 . XRD and EXAFS spectral characterizations revealed the atomically ordered intermetallic phase nature of the Ni 3 Ga-MIHMs. The selective hydrogenation of acetylene catalytic evaluation results further demonstrated excellent catalytic properties of the Ni 3 Ga-MIHMs, which results from the more energetically facile reaction pathway for acetylene hydrogenation and ethylene desorption over it as revealed by DFT calculations. Besides, this strategy is also extendable to synthesize other multi-shelled intermetallic Ni 3 Sn 4 hollow microspheres, and is expected to open up new opportunities for rational design and preparation of novel structured and highly efficient intermetallics.