Size-selected clusters are important model catalysts because of their narrow size and compositional distributions, as well as enhanced activity and selectivity in many reactions. Still, their structure-activity relationships are, in general, elusive. The main reason is the difficulty in identifying and quantitatively characterizing the catalytic active site in the clusters when it is confined within subnanometric dimensions and under the continuous structural changes the clusters can undergo in reaction conditions. Using machine learning approaches for analysis of the operando X-ray absorption near-edge structure spectra, we obtained accurate speciation of the CuPd cluster types during the propane oxidation reaction and the structural information about each type. As a result, we elucidated the information about active species and relative roles of Cu and Pd in the clusters.
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http://dx.doi.org/10.1021/acsami.1c06714 | DOI Listing |
Phys Chem Chem Phys
December 2024
National & Local Joint Engineering Research Center for Applied Technology of Hybrid Nanomaterials, Henan University, Kaifeng 475004, China.
The conversion of the highly selective CO reduction reaction (CORR) into desired value-added multicarbon compounds, like CH, is crucial, but it is mainly constrained by the high energy barrier for C-C coupling and the multi-electron transfer process. Herein, M/TiO and M/TiO-V (M = Cu, Pd, CuPd, and V refers to the surface oxygen vacancy) catalysts were designed to study the CORR towards CH by using density functional theory (DFT). We found that the surface oxygen vacancy enhances the adsorption ability of studied catalysts.
View Article and Find Full Text PDFSmall
August 2024
Institute for Nanostructure and Solid-State Physics, Center for Hybrid Nanostructures, University of Hamburg, 22761, Hamburg, Germany.
Nanocrystal self-assembly into supercrystals provides a versatile platform for creating novel materials and devices with tailored properties. While common self-assembly strategies imply the use of purified nanoparticles after synthesis, conversion of chemical precursors directly into nanocrystals and then supercrystals in simple procedures has been rarely reported. Here, the nucleation and growth of CuPd icosahedra and their consecutive assembly into large closed-packed face-centered cubic (fcc) supercrystals are studied.
View Article and Find Full Text PDFSmall
March 2024
College of Chemistry and Materials Science and, Guangdong Provincial Key Laboratory of Functional Supramolecular Coordination Materials and Applications, Jinan University, Guangzhou, 510632, P. R. China.
The construction of stable copper nanoclusters (Cu-NCs) with near-infrared (NIR) emission that can be used for catalysis is highly desired, yet remains a challenge. Herein, an atomically precise bimetallic Cu/Pd NC with a molecular formula of CuPdL(PPh)(Pz) (Pz = 3,5-(CF)Pyrazolate, L = 4-CHOPhC≡C), abbreviated as CuPd, is synthesized. Single-crystal X-ray crystallographic analysis of CuPd reveals a CuPd kernel with pseudo-gyroelongated square bipyramid confirmation surrounded by other 6 Cu(I) ions and protected ligands.
View Article and Find Full Text PDFNanomaterials (Basel)
December 2022
Department of Chemistry, School of Physical and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK.
Electrochemical CO reduction reactions can lead to high value-added chemical and materials production while helping decrease anthropogenic CO emissions. Copper metal clusters can reduce CO to more than thirty different hydrocarbons and oxygenates yet they lack the required selectivity. We present a computational characterization of the role of nano-structuring and alloying in Cu-based catalysts on the activity and selectivity of CO reduction to generate the following one-carbon products: carbon monoxide (CO), formic acid (HCOOH), formaldehyde (HC=O), methanol (CHOH) and methane (CH).
View Article and Find Full Text PDFFaraday Discuss
January 2023
Department of Nanocatalysis, J. Heyrovský Institute of Physical Chemistry v.v.i., Czech Academy of Sciences, Dolejškova 2155/3, 182 23 Prague 8, Czech Republic.
The pronounced effects of the composition of four-atom monometallic Cu and Pd and bimetallic CuPd clusters and the support on the catalytic activity and selectivity in the oxidative dehydrogenation of cyclohexene are reported. The ultra-nanocrystalline diamond supported clusters are highly active and dominantly produce benzene; some of the mixed clusters also produce cyclohexadiene, which are all clusters with a much suppressed combustion channel. The also highly active TiO-supported tetramers solely produce benzene, without any combustion to CO.
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