Designing highly active catalysts at an atomic scale is required to drive the hydrogen evolution reaction (HER). Copper-platinum (Cu-Pt) dual sites were alloyed with palladium nanorings (Pd NRs) containing 1.5 atom % Pt, using atomically dispersed Cu on ultrathin Pd NRs as seeds. The ultrafine structure of atomically dispersed Cu-Pt dual sites was confirmed with X-ray absorption fine structure (XAFS) measurements. The Pd/Cu-Pt NRs exhibit excellent HER properties in acidic solution with an overpotential of only 22.8 mV at a current density of 10 mA cm and a high mass current density of 3002 A g at a -0.05 V potential.

We report a one-pot synthesis of atomically dispersed Ru on ultrathin Pd nanoribbons. By using synchrotron radiation photoemission spectroscopy (SRPES), extended X-ray absorption fine structure (EXAFS) measurements in combination with aberration corrected high-resolution transmission electron microscopy (HRTEM), we show that atomically dispersed Ru with content up to 5.9% was on the surface of the ultrathin nanoribbon. Furthermore, the ultrathin Pd/Ru nanoribbons could remarkably prohibited the hydrogenolysis in chemoselective hydrogenation of C=C bonds, leading to an excellent catalytic selectivity compared with the commercial Pd/C and Ru/C.

Developing highly stable and efficient catalysts toward the oxygen reduction reaction is important for the long‐term operation in proton exchange membrane fuel cells. Reported herein is a facile synthesis of two‐dimensional coplanar Pt‐carbon nanomeshes (NMs) that are composed of highly distorted Pt networks (neck width of 2.05±0.72 nm) and carbon. X‐ray absorption fine structure spectroscopy demonstrated the metallic state of Pt in the coplanar Pt/C NMs. Fuel cell tests verified the excellent activity of the coplanar Pt/C NM catalyst with the peak power density of 1.21 W cm−2 and current density of 0.360 A cm−2 at 0.80 V in the H2/O2 cell. Moreover, the coplanar Pt/C NM electrocatalysts showed superior stability against aggregation, with NM structures preserved intact for a long‐term operation of over 30 000 cycles for electrode measurement, and the working voltage loss was negligible after 120 h in the H2/O2 single cell operation. Density‐functional theory analysis indicates the increased vacancy formation energy of Pt atoms for coplanar Pt/C NMs, restraining the tendency of Pt dissolution and aggregation.

The activity and stability of bimetallic nanocatalysts strongly depend on their structures, compositions, and interfaces. Here, we report the synthesis of mesoporous Pd@Ru core-shell bimetallic nanorods composed of face-centered cubic Pd and hexagonal close-packed Ru. The nanorods have two types of cavities with diameters of 3.0 ± 0.9 and 20.3 ± 8.1 nm. The mutual diffusion process between Ru and Pd is characterized by the high-angle annular dark-field scanning transmission electron microscopy, energy-dispersive X-ray spectroscopy mapping, and the synchrotron radiation photoemission spectroscopy measurements. The mesoporous Pd@Ru nanorods exhibit superior catalytic performance and stability for hydrogen evolution reactions (overpotentials of 30 mV at 10 mA·cm in 1.0 M KOH solution and 37 mV at 10 mA·cm in 0.5 M HSO solution).

Nanostructured noble metal‐based materials have been considered in recent years as promising catalysts for energy storage and conversion. One of their prominent applications is a series of electrochemical processes in fuel cells, as they show excellent electrocatalytic performance towards the reactions occurring at both anode and cathode. Nowadays, considerable efforts have been devoted to boosting the catalytic activity and minimizing the used amount of precious metals. In this review, we introduce the recent advances regarding controllable synthesis of noble metal electrocatalysts at an atomic level. Important electrochemical reactions, such as oxygen reduction reaction (ORR), hydrogen evolution reaction (HER), oxygen evolution reaction (OER), electroreduction of carbon dioxide (CO2) and so on, catalyzed by precisely controllable noble metal electrocatalysts will be highlighted. This review primarily focuses on the exploration for the relationship between atomic‐level structure of electrocatalysts and their enhanced catalytic property combining theoretical calculations and experiments. Finally, perspectives for further advances of noble metal nanomaterials are proposed to realize rational design of electrocatalysts at an atomic level.

Designing highly active catalysts at an atomic scale is required to drive the hydrogen evolution reaction (HER). Copper-platinum (Cu-Pt) dual sites were alloyed with palladium nanorings (Pd NRs) containing 1.5 atom %P t, using atomically dispersed Cu on ultrathin Pd NRs as seeds.T he ultrafine structure of atomically dispersed Cu-Pt dual sites was confirmed with X-ray absorption fine structure (XAFS) measurements.T he Pd/Cu-Pt NRs exhibit excellent HER properties in acidic solution with an overpotential of only 22.8 mV at ac urrent density of 10 mA cm À2 and ah igh mass current density of 3002 Ag À1(Pd+Pt) at a À0.05 Vpotential.

We report an atomic-scale controllable synthesis of the face-centered cubic Ru overlayers on Pd nanosheets (Pd@Ru NSs) by a solution-based epitaxial growth method. The thickness of Ru overlayers can be accurately tuned at an atomic level, which has been confirmed by atomic force microscopy and high-angle annular dark-field scanning transmission electron microscopy. After annealing in air, the Pd@Ru NSs were transformed to PdO@RuO2 NSs with rutile RuO2 epitaxially grown on the PdO. The oxygen evolution reaction (OER) activity and stability strongly depend on the atomic layers of RuO2 and ∼4 atomic layers of RuO2 (PdO@RuO2-4layers) exhibit superior stability and optimal activity for OER with only 257 mV of the overpotential to reach 10 mA cm–2. Density functional theory calculations well reproduce the thickness dependence of OER activity and reveal that O* binds more weakly on the PdO@RuO2-4layers that boosts the rate-determining step for formation of HOO*, assuring the best OER performance.

Water electrolysis, driven by earth-abundant transition-metal-based electrocatalysts, is an important reaction for sustainable energy storage. Efficient water splitting processes at electrode are kinetically limited by the improper adsorption strengthens between...