Search

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]

Electrochemical reduction of CO 2 to multi-carbon products is very attractive yet particularly challenging due to the low efficiency of C-C coupling over currently used electrocatalysts. In this work, we report a dual-atom catalyst (Cu 2 /NC) capable of selectively promoting electro-reduction of CO 2 to C 2 H 4. The Faradaic efficiency of CO 2 -to-C 2 H 4 over the Cu 2 /NC is up to ∼34.9% with a current density of 33.6 mA·cm−2. By contrast, its Cu single-atom counterpart only generates CO without forming C 2 H 4. The density functional theory (DFT) calculations reveal that the Cu-Cu sites largely promote the adsorption of *CO and reduce the energy barrier of C-C coupling between the adsorbed *CO relative to that of the single Cu sites, which accounts for the high C 2 H 4 selectivity of the Cu 2 /NC. [Display omitted] • Highly efficient Cu dual-atom catalysts were prepared to catalyze CO2RR. • Compared with Cu single-atom catalyst, dual-atom catalyst was more favorable to reduce CO2 to multi-carbon product C2H4. • DFT calculations revealed that the energy barrier of C-C coupling was largely reduced on the dual Cu catalysts. [ABSTRACT FROM AUTHOR]