Hydrolysis of ammonia borane is deemed as a promising technique for robust hydrogen production, yet its deployment is still restricted due to the sluggish kinetics of the water dissociation step. An appropriate catalyst that can effectively reduce the H₂O dissociation barrier is quite desirable for sustainable ammonia borane-to-hydrogen conversion. Herein, an amino pre-coordination confinement strategy is profiled to achieve sub-2 nm ordered PtCo intermetallics uniformly on N-doped hollow mesoporous carbon spheres (O-PtCo/NHMS) for ammonia borane catalytic hydrolysis. Such a confined approach showcases the capacity of preventing nanoparticles from agglomeration and growth for accurate size control and can be extended to other ordered intermetallic systems (e.g. PtFe and PtCu). As for the ammonia borane hydrolysis, the ordered PtCo intermetallics have delivered a five times higher turnover frequency activity of 1264.1 min⁻¹ than that of the disordered PtCo catalyst, together with excellent catalytic durability. Mechanism studies indicate that the ordered PtCo structure promotes the balanced adsorption of H₂O and ammonia borane molecules at Co and Pt sites and reduces the energy barrier for the rate-determining H₂O dissociation step to boost the ammonia borane hydrolysis. This work provides valuable insights into the rational design of efficient ordered PtM intermetallic catalysts and expands their application in hydrogen production via ammonia borane hydrolysis.

Based on the great advantages of an inner hollow structure and excellent solid counterpart capacity, complex hierarchical structures have been widely used as electrodes for lithium-ion batteries. Herein, hierarchical yolk–shell Cu₂O@CuO-decorated RGO (YSRs) was designed and synthesized via a multi-step approach. Octahedron-like Cu₂O-decorated RGO was firstly produced, in which GO was reduced slightly while cuprous oxide was synthesized. Subsequently, the controlled oxidation of Cu₂O@RGO led to the synthesis of special YSRs, which were composed of a solid Cu₂O core, spur-CuO, CuO shell, and RGO covered. As anode materials, YSRs could provide considerable capacity density. Meanwhile, the void existed between shells and solid active materials retaining the advantages of inner hollow structure. As a result, the unique architecture of the materials renders the composites with enhanced electronic and ionic diffusion kinetics, high specific capacity (~894 mAh g^-1, 0.1C), and an excellent rate capability.

To improve the atomic utilization of metals and reduce the cost of industrialization, the one-step total monoatomization of macroscopic bulk metals, as opposed to nanoscale metals, is effective. In this study, we used a thermal diffusion method to directly convert commercial centimeter-scale Ni foam to porous Ni single-atom-loaded carbon nanotubes (CNTs). As expected, owing to the coating of single-atom on porous, highly conductive CNT carriers, Ni single-atom electrocatalysts (Ni-SACs) exhibit extremely high activity and selectivity in CO₂ electroreduction (CO₂RR), yielding a current density of > 350 mA/cm², a selectivity for CO of > 91% under a flow cell configuration using a 1 M potassium chloride (KCl) electrolyte. Based on the superior activity of the Ni-SACs electrocatalyst, an integrated gas-phase electrochemical zero-gap reactor was introduced to generate a significant amount of CO current for potential practical applications. The overall current can be increased to 800 mA, while maintaining CO Faradaic efficiencies (FEs) at above 90% per unit cell. Our findings and insights on the active site transformation mechanism for macroscopic bulk Ni foam conversion into single atoms can inform the design of highly active single-atom catalysts used in industrial CO₂RR systems.