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The development of efficient electrocatalysts for the CO2 reduction reaction (CO2RR) remains a challenge. Demonstrated here is a NiSn atomic‐pair electrocatalyst (NiSn‐APC) on a hierarchical integrated electrode, which exhibits a synergistic effect in simultaneously promoting the activity and selectivity of the CO2RR to formate. The NiSn atomic pair consists of adjacent Ni and Sn, each coordinated with four nitrogen atoms (N4‐Ni‐Sn‐N4). The as‐prepared NiSn‐APC displays exceptional activity for the CO2RR to formate with a turnover frequency of 4752 h−1, a formate productivity of 36.7 mol h−1 gSn−1 and an utilization degree of active sites (57.9 %), which are superior to previously reported single‐atomic catalysts. Both experimental data and density‐functional theory calculations verify the electron redistribution of Sn imposed by adjacent Ni, which reduces the energy barrier of the *OCHO intermediate and makes this potential‐determining step thermodynamically spontaneous. This synergistic catalysis provides a successful paradigm for rational design and preparation of atomic‐pair electrocatalysts with enhanced performance. [ABSTRACT FROM AUTHOR]

• A ZrO 2− x modified Cu nanocatalyst was prepared via a facile in situ structural transformation from hydrotalcite precursors. • This Cu-based catalyst was employed for the vapor-phase hydrogenation of dimethyl oxalate to ethylene glycol. • The optimal catalyst exhibits an excellent ethylene glycol yield (99.5%) and a high turnover frequency value (42.4 h−1). • The synergistic catalysis of Cu−O−Zr3+−Vö sites offer a new reaction pathway with decreased activation energy. Carbon-oxygen bond hydrogenation serves as a versatile fundamental reaction extensively applied in chemicals synthesis, but rational design of heterogeneous catalysts with satisfactory catalytic performance and stability remains a big challenge. Herein, a ZrO 2-x modified Cu nanocatalyst with unique interfacial structure Cu-O-Zr3+-Vö (Vö denotes oxygen vacancy), was elaborately designed and prepared via a facile in situ structural transformation from layered double hydroxide precursors, confirmed by a comprehensive study including HADDF-STEM, in situ EXAFS and quasi in situ XPS measurements. The optimized catalyst (Cu/ZrO 2-x -S3) exhibits an extremely high catalytic performance toward dimethyl oxalate (DMO) hydrogenation to ethylene glycol (EG), with a yield of 99.5 %. Notably, the turnover frequency (TOF) value and space time yield of EG reach up to 42.4 h−1 and 1.05 g EG ⋅g cat −1⋅h−1, respectively. This is, to the best of our knowledge, the highest level compared with previously reported Cu-based catalysts under similar conditions. In addition, the in situ investigations (in situ DMO-FTIR, in situ DMO-EXAFS) and catalytic evaluations substantiate interfacial sites serve as active center: the Zr3+-Vö facilitates adsorption and activation of C O/C O groups; whilst H 2 molecule undergoes dissociation at the interfacial Cu species, followed by hydrogen spillover onto Cu-O-Zr for hydrogenation of activated C O/C O bonds. This interfacial synergistic catalysis offers a new reaction pathway with decreased activation energy, accounting for the resulting superior catalytic performance, which can be extended to other carbon-oxygen bonds hydrogenation systems. [ABSTRACT FROM AUTHOR]

• Activity and stability of Ga/ZSM-5 were improved by H 2 -O 2 treatment. • Effective balance of dehydrogenation and cracking of Ga/ZSM-5 was achieved. • Activation energy was decreased largely for Ga/ZSM-5 after H 2 -O 2 treatment. • The mechanism of butane-O 2 treatment on Ga/ZSM-5 was proposed. Ga species with high dehydrogenation capability were prepared by H 2 -O 2 atmosphere treatment, and efficient balance of bifunctionality (dehydrogenation/cracking) was realized between Ga species and ZSM-5 over Ga/ZSM-5 based catalysts. Compared with parent Ga/ZSM-5, the conversion rate of n -butane was increased from 0.53 to 2.59 mmol·g−1·min−1 on Ga/ZSM-5 with H 2 -O 2 treatment. Kinetic analysis revealed that the apparent activation energy of n -butane catalytic cracking decreased largely from 141 to 47 kJ·mol−1, which is attributed to the formation of new interaction between Ga species and ZSM-5 upon such an atmosphere treatment. It was also found Butane-O 2 treatment acted as a similar role with H 2 -O 2 treatment in enhancing the catalytic performance. On this basis, different Ga species were correlated with activity and kinetic data, and the effect of practical reaction atmosphere on Ga species was also investigated. [ABSTRACT FROM AUTHOR]