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[Display omitted] • An effective strategy has been established by doping Ce into Cu NPs to tune the electronic state of Cu. • It attains the faradaic efficiency of C 2 H 4 as high as 53% with a current density of 150 mA/cm2. • Such performance is about 2.8-fold increase when compared with Cu NPs. • The electronic structure regulation and defective sites facilitate highly efficient C 2 H 4 production from CO 2 electroreduction. Coupling another metal element tends to produce catalytic controls of high activity and selectivity. However, this action is still poorly explored to improve the selectivity of the electroreduction of CO 2 to C 2 H 4 with high energy density. Herein, Ce-doped Cu nanoparticles (Ce-Cu NPs) are synthesized by one-step co-reduction method and presented a preferable example that promotes selective transformation of CO 2 to C 2 H 4 in a flow-cell configuration. Thereinto, high faradaic efficiency (FE) of C 2 H 4 for Ce-Cu-2 NPs could reach 53% with the current density of 150 mA cm−2, which is 2.8 times higher than that of Cu NPs. The outstanding performance mainly stems from tailoring the doped-Ce content shrinks particle sizes and forms oxygen defects due to the electron effect of nearby Ce atoms, boosting local electronic re-distribution of Cu. Meanwhile, in-situ Raman spectroscopies evidenced that the doping of Ce can enhance Cu site to bond *CO, which were beneficial to C–C coupling and thus endowed the catalyst with the superior catalytic performance in CO 2 electroreduction toward C 2 H 4. [ABSTRACT FROM AUTHOR]

Robust ZPOFs with multiple active sites are facilely constructed and show remarkable CO 2 adsorption and conversion performance under mild/green conditions. [Display omitted] • Novel ZPOFs with multiple active sites are prepared via ionothermal polymerization. • The ZPOFs show exciting dual-functions for CO 2 adsorption and conversion. • The ZPOF-mediated CO 2 coupling reaction can proceed under mild/green conditions. • The present ZPOF is easily separated and shows good stability and reusability. • The optimum catalyst exhibits excellent broad substrate scope. Porous organic frameworks fabricated by well-defined monomeric compounds with different active sites have been regarded as the promising nano-materials for improving the efficiency of CO 2 capture and utilization. In this study, novel zwitterionic porous organic frameworks (ZPOFs) alternately connected by benzimidazole, triazine and imidazolium modules were prepared facilely via ZnCl 2 -catalyzed bi-component polymerization. The influences of different monomer concentration and polymerization temperature on structural properties of the ZPOFs were discussed in detail. It indicates that the ZPOFs present attractive structure characteristics of high specific surface area and hierarchical pore structure, and have abundant hydrogen bond donors, Lewis bases and nucleophilic groups, respectively. The ZPOFs as-obtained were applied to CO 2 adsorption and conversion into cyclic carbonate by coupling with epoxide. The experiment results showed that the ZPOFs could afford the highest CO 2 adsorption capacity of 2505 μmol/g at 273 K and 1.0 bar CO 2 pressure. The effects of ZPOFs structures and reactions conditions on the catalytic performance were investigated. Under the optimized conditions of 70 °C, 2.0 MPa CO 2 for 2.0 h, and cooperating with tetrabutylammonium iodide (TBAI) cocatalyst, the ZPOF-450–30 could efficiently and selectively catalyze the CO 2 /epoxides cycloaddition reaction to yield corresponding cyclic carbonates. Moreover, the ZPOF-450–30 catalyst could be simply separated with durable high stability and activity. Finally, we compared the catalytic behaviors with reported similar heterogeneous catalysts and proposed a feasible ZPOFs-catalyzed mechanism. [ABSTRACT FROM AUTHOR]