An urchin-like sulphide-derived bismuth electrocatalyst was synthesised for CO₂reduction and a maximum of 84.0% faradaic efficiency for formate formation was achieved. The origin of the activity of the sulphide-derived bismuth catalyst was explored and its defect-rich structure was responsible for the high formate selectivity.

Developing ruthenium-based oxide catalysts capable of suppressing lattice oxygen participation in the catalytic reaction process is crucial for maintaining stable oxygen evolution reaction (OER) under acidic conditions. Herein, we delicately construct a RuO₂ nanoparticle-anchored LiCoO₂ nanosheet electrocatalyst (RuO₂/LiCoO₂), achieving dynamic optimization of RuO₂ during the reaction process and improving catalytic stability. Benefiting from the unique electrochemical delithiation characteristics of the LiCoO₂ support, the covalency of the Ru-O bond is effectively regulated during the OER process. The weakened Ru-O covalent bond inhibits the participation of lattice oxygen in the catalytic reaction and ensures the continuous operation of the Ru active sites. Moreover, the extended Ru-O bond in the optimized RuO₂/LiCoO₂ catalyst reduces the formation energy barrier of the *OOH intermediates, accelerating the progress of the OER. As a result, the RuO₂/LiCoO₂ catalyst requires only an overpotential of 150 ± 2 mV at 10 mA cm⁻² in 0.5 M H₂SO₄ and operates stably for 2000 h at 1 A cm⁻² in a proton exchange membrane water electrolysis. This work opens new avenues for designing efficient ruthenium-based catalysts.

Electrocatalytic CO₂ reduction is a promising way to mitigate the urgent energy and environmental issues, but how to increase the selectivity for desired product among multiple competing reaction pathways remains a bottleneck. Here, we demonstrate that engineering the gas–liquid–solid contact interface on the electrode surface could tailor the selectivity of CO₂ reduction and meanwhile suppress H₂ production through regulated reaction kinetics. Specifically, polytetrafluoroethylene (PTFE) was utilized to modify a Cu nanoarray electrode as an example, which is able to change the electrode surface from aerophobic to aerophilic state. The enriched nano-tunnels of the Cu nanoarray electrode can facilitate CO₂ transportation and pin gaseous products on the electrode surface. The latter is believed to be the reason that boosts the Faradaic efficiency of liquid products by 67% and limits the H₂ production to less than half of before. This interface engineering strategy also lowered H₂O (proton) affinity, therefore promoting CO and HCOOH production. Engineering the electrode contact interface controls the reaction kinetics and the selectivity of products, which should be inspiring for other electrochemical reactions.

Realizing an efficient turnover frequency in the acidic oxygen evolution reaction by modifying the reaction configuration is crucial in designing high-performance single-atom catalysts. Here, we report a “single atom–double site” concept, which involves an activatable inert manganese atom redox chemistry in a single-atom Ru-Mn dual-site platform with tunnel Ni ions as the trigger. In contrast to conventional single-atom catalysts, the proposed configuration allows direct intramolecular oxygen coupling driven by the Ni ions intercalation effect, bypassing the secondary deprotonation step instead of the kinetically sluggish adsorbate evolution mechanism. The strong bonding of Ni ions activates the inert manganese terminal groups and inhibits the cross-site disproportionation process inherent in the Mn scaffolding, which is crucial to ensure the dual-site platform. As a result, the single-atom Ru-Ni-Mn octahedral molecular sieves catalyst delivers a low overpotential, adequate mass activity and good stability.

Cu catalyses electrochemical CO₂ reduction to valuable multicarbon products but understanding the structure-function relationship has remained elusive due to the active Cu sites being heterogenized and under dynamic re-construction during electrolysis. We herein coordinate Cu with six phenyl-1H-1,2,3-triazole derivatives to form stable coordination polymer catalysts with homogenized, single-site Cu active sites. Electronic structure modelling, X-ray absorption spectroscopy, and ultraviolet–visible spectroscopy show a widely tuneable Cu electronics by modulating the highest occupied molecular orbital energy of ligands. Using CO diffuse reflectance Fourier transform infrared spectroscopy, in-situ Raman spectroscopy, and density functional theory calculations, we find that the binding strength of *CO intermediate is positively correlated to highest occupied molecular orbital energies of the ligands. As a result, we enable a tuning of C–C coupling efficiency—a parameter we define to evaluate the efficiency of C₂ production—in a broad range of 0.26 to 0.86. This work establishes a molecular platform that allows for studying structure-function relationships in CO₂ electrolysis and devises new catalyst design strategies appliable to other electrocatalysis.