Electrocatalytic CO₂ reduction reaction (CO₂RR) can store and transform the intermittent renewable energy in the form of chemical energy for industrial production of chemicals and fuels, which can dramatically reduce CO₂ emission and contribute to carbon-neutral cycle. Efficient electrocatalytic reduction of chemically inert CO₂ is challenging from thermodynamic and kinetic points of view. Therefore, low-cost, highly efficient, and readily available electrocatalysts have been the focus for promoting the conversion of CO₂. Very recently, interface engineering has been considered as a highly effective strategy to modulate the electrocatalytic performance through electronic and/or structural modulation, regulations of electron/proton/mass/intermediates, and the control of local reactant concentration, thereby achieving desirable reaction pathway, inhibiting competing hydrogen generation, breaking binding-energy scaling relations of intermediates, and promoting CO₂ mass transfer. In this review, we aim to provide a comprehensive overview of current developments in interface engineering for CO₂RR from both a theoretical and experimental standpoint, involving interfaces between metal and metal, metal and metal oxide, metal and nonmetal, metal oxide and metal oxide, organic molecules and inorganic materials, electrode and electrolyte, molecular catalysts and electrode, etc. Finally, the opportunities and challenges of interface engineering for CO₂RR are proposed.

By modulating the d band center via dual metal doping, and thus optimizing the adsorption free energy change for intermediates, the as prepared Ni–Mn–FeP exhibits outstanding catalytic performance toward both the OER ( η ₁₀ = 185 mV) and HER ( η ₁₀ = 103 mV).

Electroreduction of greenhouse gas CO₂ into value-added fuels and chemicals provides a promising pathway to address the issues of energy crisis and environmental change. However, the regulations of the selectivity towards C₂ product and the competing hydrogen evolution reaction (HER) are major challenges for CO₂ reduction reaction (CO₂RR). Here, we develop an interface-enhanced strategy by depositing a thin layer of nitrogen-doped graphene (N-G) on a Cu foam surface (Cu-N-G) to selectively promote the ethanol pathway in CO₂RR. Compared to the undetectable ethanol selectivity of pure Cu and Cu@graphene (Cu-G), Cu-N-G has boosted the ethanol selectivity to 33.1% in total Faradic efficiency (FE) at −0.8 V vs. reversible hydrogen electrode (RHE). The experimental and density functional theory (DFT) results verify that the interconnected graphene coating can not only serve as the fast charge transport channel but also provide confined nanospace for mass transfer. The N doping can not only trigger the intrinsic interaction between N in N-G and CO₂ molecule for enriching the local concentration of reactants but also promote the average valence state of Cu for C-C coupling pathways. The confinement effect at the interface of Cu-N-G can not only provide high adsorbed hydrogen (H_ad) coverage but also stabilize the key ⋆HCCHOH intermediate towards ethanol pathway. The provided interface-enhanced strategy herein is expected to inspire the design of Cu-based CO₂RR electrocatalysts towards multi-carbon products.

The catalytic conversion of carbon dioxide (CO₂) into high value-added chemicals is of great significance to address the pressing carbon cycle issues. Reticular chemistry of metal-organic frameworks (MOFs)-based materials exhibits great potential and effectiveness to face CO₂ challenge from capture to conversion. To date, the integrated nanocomposites of nanostructure and MOF have emerged as a powerful heterogeneous catalysts featured with multifold advantages including synergistic effects between the two interfaces, confinement effect of meso- and micropores, tandem reaction triggered by multiple active sites, high stability and dispersion, and so on. Given burgeoning carbon cycle and nanostructure@MOFs, this review highlights some of important advancements to provide a full understanding on the synthesis and design of nanostructure@MOFs composites to facilitate carbon cycle through CO₂ photocatalytic, electrocatalytic, and thermal conversion. Afterward, the catalytic applications of some representative nanostructure@MOFs composites are categorized, in which the origin of activity or structure-activity relationship is summarized. Finally, the opportunities and challenges are proposed for inspiring the future development of nanostructure@MOFs composites for carbon cycle.