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Electrochemical CO2 reduction (ECR) is becoming an increasingly important technology for achieving carbon neutrality. Inspired by the structure of naturally occurring Mo‐dependent enzymes capable of activating CO2, a heteronuclear Mo–Se dual‐single‐atom electrocatalyst (MoSA–SeSA) for ECR into CO with a Faradaic efficiency of above 90% over a broad potential window from −0.4 to −1.0 V versus reversible hydrogen electrode is demonstrated here. Both operando characterization and theoretical simulation results verify that MoSA acts as central atoms that directly interact with the ECR feedstock and intermediates, whereas the SeSA adjacent to MoSA modulates the electronic structure of MoSA through long‐range electron delocalization for inhibiting MoSA poisoning caused by strong CO adsorption. In addition, the SeSAs far from MoSA help suppress the competing hydrogen evolution side reaction and accelerate the CO2 transport by repelling H2O. This work provides new insight into the precise regulation and in‐depth understanding of multisite synergistic catalysis at the atomic scale.

As the most well-known electrocatalyst for cathodic hydrogen evolution in water splitting electrolyzers, platinum is unfortunately inefficient for anodic oxygen evolution due to its over-binding with oxygen species and excessive dissolution in oxidative environment. Herein we show that single Pt atoms dispersed in cobalt hydrogen phosphate with an unique Pt(OH)(O3)/Co(P) coordination can achieve remarkable catalytic activity and stability for oxygen evolution. The catalyst yields a high turnover frequency (35.1 ± 5.2 s−1) and mass activity (69.5 ± 10.3 A mg−1) at an overpotential of 300 mV and excellent stability. Mechanistic studies elucidate that the superior catalytic performance of isolated Pt atoms herein stems from optimal binding energies of oxygen intermediate and also their strong electronic coupling with neighboring Co atoms that suppresses the formation of soluble Ptx>4 species. Alkaline water electrolyzers assembled with an ultralow Pt loading realizes an industrial-level current density of 1 A cm−2 at 1.8 volts with a high durability.

Hydrogen evolution reaction (HER) in neutral media is of great practical importance for sustainable hydrogen production, but generally suffers from low activities, the cause of which has been a puzzle yet to be solved. Herein, by investigating the synergy between Ru single atoms (RuNC) and RuSex cluster compounds (RuSex) for HER using ab initio molecular dynamics, operando X-ray absorption spectroscopy, and operando surface-enhanced infrared absorption spectroscopy, we establish that the interfacial water governs neutral HER. The rigid interfacial water layer in neutral media would inhibit the transport of H2O*/OH* at the electrode/electrolyte interface of RuNC, but the RuSex can promote H2O*/OH* transport to increase the number of available H2O* on RuNC by disordering the interfacial water network. With the synergy of RuSex and RuNC, the resulting neutral HER performance in terms of mass-specific activity is 6.7 times higher than that of 20 wt.% Pt/C at overpotential of 100 mV.

Dual regulation of active sites and kinetics via Mn heteroatom doping engineering in pyrite NiS2 for boosting alkaline and neutral hydrogen evolution.

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The development of highly active catalysts for ammonia selective catalytic reduction (NH 3 -SCR) of NO at low temperatures and the exploration of efficient catalytic active sites are desirable but still challenging. Herein, a series of Fe x Mn 3−x O 4 nanoparticles (NPs) were synthesized, derived from Mn−Fe bimetallic MOFs. The Fe 0.35 Mn 2.65 O 4 NPs exhibit a NO conversion up to 90% at 180 °C in an ultrahigh GHSV of 400 000 h −1 . An efficient Fe oct −O−Mn tet site is revealed, and the formation energy of oxygen vacancy on the Fe oct −O−Mn tet site is the lowest, which is the rate-determining step of NO oxidation. The high NO oxidation activity can trigger the "fast SCR" reaction, thus leading to the boosted NH 3 -SCR performance. This work provides not only an approach to construct NH 3 -SCR catalysts with high intrinsic activity but also the potential to resolve industrial challenges related to NO catalytic reduction.