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Jiang D, Shi Y, Zhou L, Ma J, Pan H, Lin Q. Promotional Effect of Nitrogen-doped and Pore Structure for the direct synthesis of Hydrogen Peroxide from Hydrogen and Oxygen by Pd/C Catalyst at Ambient Pressure. ARAB J CHEM 2022. [DOI: 10.1016/j.arabjc.2022.104452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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Silica Bifunctional Supports for the Direct Synthesis of H2O2: Optimization of Br/Acid Sites and Pd/Br Ratio. Catalysts 2022. [DOI: 10.3390/catal12070796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
We have studied the direct synthesis of hydrogen peroxide using a catalytic system consisting of palladium supported on silica bifunctionalized with sulfonic acid groups and bromide in the absence of acid and halide promoters in solution. Catalysts with several bromide substituents were employed in the catalyst synthesis. The prepared samples were characterized by TXRF, XPS, and hydrogen peroxide decomposition. Catalysts characterization indicated the presence of only palladium (II) species in all of the samples, with similar values for surface and bulk of Pd/Br atomic ratio. The catalysts were tested via direct synthesis, and all samples were able to produce hydrogen peroxide at 313 K and 5.0 MPa. The hydrogen peroxide yield and selectivity changed with the Pd/Br ratio. A decrease in the Pd/Br ratio increases the final hydrogen peroxide concentration, and the selectivity for H2O2 reaches a maximum at a Pd/Br ratio around 0.16 and then decreases. However, the maximum hydrogen peroxide concentration and selectivity occur at slightly different Pd/Br ratios, i.e., resp. 0.4 vs. 0.16.
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Lee HW, Jung E, Han GH, Kim MC, Kim D, Lee KY, Han SS, Yu T. Three-in-One Strategy to Improve Both Catalytic Activity and Selectivity: Nonconcentric Pd-Au Nanoparticles. J Phys Chem Lett 2021; 12:11098-11105. [PMID: 34752106 DOI: 10.1021/acs.jpclett.1c03256] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
In direct H2O2 synthesis, the Pd-Au alloy was considered as a potential catalyst because of its much better performance compared to the prototype Pd; unfortunately, achieving both high activity and selectivity remains a challenge. Here, we synthesized nonconcentric Pd-Au NPs in which Au domain shells are formed only partially on Pd domain cores and tested them for direct H2O2 synthesis. It has three exposed regions of Pd, Au domains, and Pd-Au interfaces in a single NP (hence, a 3-in-1 strategy). Creating nonconcentric forms was demonstrated convincingly by density functional theory calculations. The nonconcentric Pd-Au particles exhibit high and well-balanced performances that are hard to achieve with traditional alloyed Pd-Au. The number of Pd/Au interfaces was found to be the key factor and thus was optimized by controlling the Au precursor concentrations. The hitherto underutilized structure of nonconcentric bimetallic alloys can be useful and thus should be more actively investigated for catalyst development.
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Affiliation(s)
- Hong Woo Lee
- Computational Science Research Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
- Department of Chemical and Biological Engineering, Korea University, 145 Anam-ro, Seoul 02841, Republic of Korea
| | - Euiyoung Jung
- Department of Chemical Engineering, Integrated Engineering Major, Kyung Hee University, Yongin 17104, Republic of Korea
| | - Geun-Ho Han
- Department of Chemical and Biological Engineering, Korea University, 145 Anam-ro, Seoul 02841, Republic of Korea
| | - Min-Cheol Kim
- Computational Science Research Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
| | - Donghun Kim
- Computational Science Research Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
| | - Kwan-Young Lee
- Department of Chemical and Biological Engineering, Korea University, 145 Anam-ro, Seoul 02841, Republic of Korea
| | - Sang Soo Han
- Computational Science Research Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
| | - Taekyung Yu
- Department of Chemical Engineering, Integrated Engineering Major, Kyung Hee University, Yongin 17104, Republic of Korea
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