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Strengthening OH adsorption on electrocatalyst is crucial to promote the rate‐determining water dissociation step of alkaline hydrogen evolution reaction (HER), whereas too‐intensified OH adsorption will poison the active sites instead. This dilemma remains one of the major challenges for improving the electrocatalysts' alkaline HER activities. Herein, a surprising finding that the strongly adsorbed OH on an ultrafine quinary PtCoCuNiZn nanoalloy can be facilely desorbed via a unique gradient OH desorption pattern is reported, which tremendously boosts its alkaline HER activity. Theoretical simulations unravel that the ultrafine PtCoCuNiZn nanoalloy possesses versatile metal sites for adsorbing OH and the strongly adsorbed OH can be gradiently transferred to desorb from the ultrafine PtCoCuNiZn nanoalloy with moderate energy barriers for each transfer step that is the gradient OH desorption. In the meanwhile, the unique gradient OH desorption mode on the ultrafine PtCoCuNiZn nanoalloy is also experimentally evidenced by the in situ Raman spectroscopy and cyclic voltammetry measurements. This finding offers a fresh opportunity to expedite the alkaline HER without compromising the OH adsorption strength on electrocatalysts, which thus maximally promotes their water dissociation properties and unlocks the full potential of their alkaline HER activities. [ABSTRACT FROM AUTHOR]

Converting CO2 to value‐added chemicals, e. g., CH3OH, is highly desirable in terms of the carbon cycling while reducing CO2 emission from fossil fuel combustion. Cu‐based nanocatalysts are among the most efficient for selective CO2‐to‐CH3OH transformation; this conversion, however, suffers from low reactivity especially in the thermodynamically favored low temperature range. We herein report ultrasmall copper (Cu) nanocatalysts supported on crystalline, mesoporous zinc oxide nanoplate (Cu@mZnO) with notable activity and selectivity of CO2‐to‐CH3OH in the low temperature range of 200–250 °C. Cu@mZnO nanoplates are prepared based on the crystal‐crystal transition of mixed Cu and Zn basic carbonates to mesoporous metal oxides and subsequent hydrogen reduction. Under the nanoconfinement of mesopores in crystalline ZnO frameworks, ultrasmall Cu nanoparticles with an average diameter of 2.5 nm are produced. Cu@mZnO catalysts have a peak CH3OH formation rate of 1.13 mol h−1 per 1 kg under ambient pressure at 246 °C, about 25 °C lower as compared to that of the benchmark catalyst of Cu−Zn−Al oxides. Our new synthetic strategy sheds some valuable insights into the design of porous catalysts for the important conversion of CO2‐to‐CH3OH. [ABSTRACT FROM AUTHOR]

Due to the surface inhomogeneity of the solid supports, direct growth of uniform bimetallic nanoparticles (NPs) with controllable structure and size thereon is particularly challenging. Herein, a surface‐confinement strategy is reported to directly prepare ultrafine bimetallic PtM NPs (MFe, Cu, and Co) with structure of core‐shell or intermetallic compounds on an N functionalized carbon support (NC). It is found that the N species of NC support can atomically disperse metal cations of precursors, which largely renders uniform nucleation and growth of bimetallic NPs and fine structure modulation of them. In another regard, metal transfer is confined to a narrow region on NC via N‐mediation, hence greatly favoring localized particle growth and formation of ultrafine bimetallic NPs. Remarkably, the ultrafine 3.1 ± 0.7 nm intermetallic Pt3Fe NPs on NC displayed excellent catalytic activity and durability toward electrochemical hydrogen evolution reaction. [ABSTRACT FROM AUTHOR]

It is extremely challenging to controllably synthesize rare earth‐containing nanoalloys due to the ultralow standard reduction potential of rare earth metals. Here, a surface‐confined strategy to prepare ultrafine Pt‐rare earth nanoalloys on a series of N‐functionalized supports is reported. It proves that by surface N‐metal coordination, the metal cations of precursors are atomically dispersed on support, which greatly favors uniform nucleation and growth of particles upon reduction. Moreover, the moderate metal transfer barrier from N ensures particle growth in a confined region to form ultrafine nanoalloys. Using this method, ultrafine PtLa, PtY, and PtDy nanoalloys are prepared on N‐functionalized supports such as carbon, zeolite, and Al2O3. Notably, the PtLa nanoalloys on N‐functionalized zeolite show superior activity and durability for propane oxidation. The strategy is expected to provide guidelines for preparing highly efficient rare earth‐containing nanoalloys for catalysis applications. [ABSTRACT FROM AUTHOR]