Controversial results still exist about the activities of tetrahedral (Co2+) and octahedral (Co3+) sites in Co3O4 toward the OER. Theoretical and experimental data confirm that octahedral sites are responsible for the OER, using model catalysts.

Single‐atom catalysts have attracted much attention. Reported herein is that regulating charge transfer of lattice oxygen atoms in serial single‐atom‐doped titania enables tunable hydrogen evolution reaction (HER) activity. First‐principles calculations disclose that the activity of lattice oxygen for the HER can be regularly promoted by substituting its nearest metal atom, and doping‐induced charge transfer plays an essential role. Besides, the realm of the charge transfer of the active site can be enlarged to the second nearest atom by creating oxygen vacancies, resulting in further optimization for the HER. Various single‐atom‐doped titania nanosheets were fabricated to validate the proposed model. Taking advantage of the localized charge transfer to the lattice atom is demonstrated to be feasible for realizing precise regulation of the electronic structures and thus catalytic activity of the nanosheets.

Water electrolysis operating in alkaline environments is a promising route to produce H2 on a massive scale. In this context, designing highly‐active and low‐cost electrocatalysts is of great importance. Here NiPt alloys with plenty of atomically dispersed Pt at the edges to boost hydrogen evolution in alkaline solution are reported. The formed Ni‐Pt atomic pairs at the edges hold engineered electronic structures by reducing the number of coordination atoms to facilitate the kinetically sluggish Volmer step, and further promote the hydrogen coupling step by providing separate active sites as well. With a Pt content of 3at%, this catalyst records an ultralow overpotential of 6 mV to reach the current density of 10 mA cm−2, and delivers a current density of 68.3 mA cm−2 at the overpotential of 30 mV, exceeding that of the commercial 20wt% Pt/C catalyst by a factor of >4. The aberration‐corrected transmission electron microscopy and quasi‐operando X‐ray absorption fine structure measurements show Ni‐Pt atomic pairs serve as active sites and enable the subtle adsorption/desorption balances between various intermediates (OH* and H*) during the hydrogen evolution reaction. The as‐made alloys show high stability with negligible activity decay after a 12 h chronoamperometric test, addressing its feasibility in an overall water‐splitting cell.

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Precise catalysis is critical for the high-quality catalysis industry. However, it remains challenging to fundamentally understand precise catalysis at the atomic orbital level. Herein, we propose a new strategy to unravel the role of specific d orbitals in catalysis. The oxygen reduction reaction (ORR) catalyzed by atomically dispersed Pt/Co-doped Ti 1−x O 2 nanosheets (Pt 1 /Co 1 -Ti 1−x O 2 ) is used as a model catalysis. The z-axis d orbitals of Pt/Co-Ti realms dominate the O 2 adsorption, thus triggering ORR. In light of orbital-resolved analysis, Pt 1 /Co 1 -Ti 1−x O 2 is experimentally fabricated, and the excellent ORR catalytic performance is further demonstrated. Further analysis reveals that the superior ORR performance of Pt 1 -Ti 1−x O 2 to Co 1 -Ti 1−x O 2 is ascribed to stronger activation of Ti by Pt than Co via the d-d hybridization. Overall, this work provides a useful tool to understand the underlying catalytic mechanisms at the atomic orbital level and opens new opportunities for precise catalyst design.