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A series of hierarchical nanosheet array-like Co-Al layered double hydroxides (LDHs)/reduced graphene oxide (rGO) hybrid supported ultrafine PdCu nanocluster (NC) catalysts PdCu/LDHs/rGO (: Cu/Pd molar ratio of 1.5, 3.0, and 5.5; : Pd loadings of ∼0.80, 0.40, 0.11, and 0.01 wt %) were assembled via an ultrasonic-assisted NaBH reduction-sol immobilization strategy. The as-obtained catalysts display ultrafine PdCu alloy NCs with sizes of ∼0.9-1.8 nm finely tuned by both Cu/Pd ratios and Pd loadings and mainly distributed on the edge sites of LDH nanosheets and part of LDHs-rGO junctions upon the unique hierarchical nanosheet array-like structure. Three catalysts 0.85-PdCu/LDHs/rGO, 0.83-PdCu/LDHs/rGO, and 0.80-PdCu/LDHs/rGO exhibit excellent Heck reactivity for iodobenzene with styrene, of which the 0.83-PdCu/LDHs/rGO shows the highest activity, much higher than Pd/LDHs/rGO and single LDHs or GO supported PdCu catalysts, attributed to the ultrafine PdCu NCs, the largest electron density of the Pd center, and the strongest PdCu NCs-LDHs-rGO three-phase synergistic effect. The lowest Pd-loading sample 0.01-PdCu/LDHs/rGO shows an unprecedented turnover frequency of 210 000 h (Pd dosage: 2 × 10 mol %) with the highest value so far, excellent adaptability for substrates, and reusability. The present work provides a versatile method for designing hierarchically structured ultrafine Pd-M alloy NC catalysts for varied catalysis processes.
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http://dx.doi.org/10.1021/acsami.0c09106 | DOI Listing |
J Colloid Interface Sci
December 2023
State Key Laboratory of Applied Organic Chemistry, Laboratory of Special Function Materials and Structure Design of the Ministry of Education, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, PR China. Electronic address:
The selective hydrogenation of alkynes to alkenes is widely applied in the chemical industry; nevertheless, achieving highly selective hydrogenation with high catalytic activity is considerably challenging. Herein, ultrafine PdCu bimetallic nanoparticles encapsulated by high-surface-area mesoporous α-AlO were prepared by high-temperature calcination-reduction using a porous organic framework (POF) as the template. As-obtained PdCu@α-AlO exhibited a high selectivity of 95% for the semi-hydrogenation of phenylacetylene as a probe reaction under mild reaction conditions.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
June 2023
Hefei National Research Center for Physical Sciences at the Microscale, Department of Chemistry, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), University of Science and Technology of China, Hefei, Anhui, 230026, P. R. China.
The chemical microenvironment modulation of metal nanoparticles (NPs) holds promise for tackling the long-lasting challenge of the trade-off effect between activity and selectivity in catalysis. Herein, ultrafine PdCu NPs incorporated into covalent organic frameworks (COFs) with diverse groups on their pore walls have been fabricated for the semihydrogenation of alkynes. The Cu species, as the primary microenvironment of Pd active sites, greatly improves the selectivity.
View Article and Find Full Text PDFJ Colloid Interface Sci
August 2023
Shenzhen Key Laboratory of Flexible Printed Electronics Technology, and School of Materials Science and Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China. Electronic address:
Bifunctional catalysts for ethanol oxidation reaction (EOR) and oxygen reduction reaction (ORR) with high noble-metal utilization are highly beneficial to direct ethanol fuel cells (DEFCs). This study developed a ternary bifunctional catalyst composed of ultrafine PtPdCu alloy nanoparticles and carbon nanotubes (CNTs) support through a facile surfactant-free solvothermal route. The carboxyl terminal groups on CNTs ensure the confined growth of PtPdCu alloys (∼5 nm) and suppress Ostwald ripening of metallic active sites during electrochemical cycling.
View Article and Find Full Text PDFPhys Chem Chem Phys
February 2023
College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, 730000, P. R. China.
Selective hydrogenation of alkynes to obtain alkenes is a key reaction in petrochemical and fine chemical industries. However, the development of stable and highly selective catalysts with uniformly dispersed active sites is still immensely challenging for the semi-hydrogenation of alkynes. In this study, N-doped porous carbon nanospheres (NPCNs) were synthesized by the nanoemulsion self-assembly and subsequently carbonization method.
View Article and Find Full Text PDFNanoscale
February 2021
Department of Chemical and Biological Engineering, University of British Columbia, 2360 East Mall, Vancouver, BC V6 T 1Z3, Canada.
Rational synthesis of bi- or multi-metallic nanomaterials with both dendritic and porous features is appealing yet challenging. Herein, with the cubic CuO nanoparticles composed of ultrafine CuO nanocrystals as a self-template, a series of Pd-Cu nanocrystals with different morphologies (e.g.
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