1
|
Tan L, Xiang G, Liu Z. Thermally stable Pd/CeO 2@SiO 2 with a core-shell structure for catalytic lean methane combustion. NANOSCALE 2024. [PMID: 38494927 DOI: 10.1039/d3nr06620g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
Noble metal catalysts exhibit high catalytic activity in lean CH4 combustion at low temperatures. However, the high surface energy of noble metal nanoparticles makes them susceptible to deactivation due to migratory-aggregation during the catalytic process. Herein, a core-shell structure with a Pd/CeO2 core and a SiO2 shell (denoted as Pd/CeO2@SiO2) was designed and prepared to enhance the thermal stability for catalytic lean CH4 combustion. A series of characterization methods demonstrated the successful encapsulation of SiO2 and the modified thermal stability. The results of activity tests indicated that Pd/CeO2@SiO2 exhibited the optimal catalytic performance. After seven runs, Pd/CeO2@SiO2 achieved 90% conversion of CH4 at 385 °C compared to Pd/CeO2 at 440 °C. The remarkable catalytic performance was attributed to the synergistic effect of strengthened metal-support interactions and the core-shell structure. On the one hand, the migration and aggregation of Pd nanoparticles were limited due to the protection of the SiO2 shell layer. On the other hand, the SiO2 shell layer further enhanced the interactions between the Pd nanoparticles and CeO2, thus promoting the formation of PdxCe1-xO2-δ solid solutions and active oxygen species, which were beneficial for the improvement of the stability and redox capacity of the catalyst.
Collapse
Affiliation(s)
- Linyan Tan
- Advanced Catalytic Engineering Research Centre of the Ministry of Education, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, China.
| | - Ganghua Xiang
- Advanced Catalytic Engineering Research Centre of the Ministry of Education, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, China.
| | - Zhigang Liu
- Advanced Catalytic Engineering Research Centre of the Ministry of Education, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, China.
| |
Collapse
|
2
|
An Y, Chatterjee P, Naik P, Banerjee S, Huang W, Slowing II, Venditti V. Hydrogen spillover and substrate-support hydrogen bonding mediate hydrogenation of phenol catalyzed by palladium on reducible metal oxides. Chem Sci 2023; 14:14166-14175. [PMID: 38098721 PMCID: PMC10717535 DOI: 10.1039/d3sc02913a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 11/09/2023] [Indexed: 12/17/2023] Open
Abstract
Substrate-support interactions play an important role in the catalytic hydrogenation of phenolic compounds by ceria-supported palladium (Pd/CeO2). Here, we combine surface contrast solution NMR methods and reaction kinetic assays to investigate the role of substrate-support interactions in phenol (PhOH) hydrogenation catalyzed by titania-supported palladium (Pd/TiO2). We show that PhOH adsorbs on the catalyst via a weak hydrogen-bonding interaction between the -OH group of the substrate and one oxygen atom on the support. Interestingly, we observe that the addition of 20 mM inorganic phosphate results in a ∼2-fold destabilization of the PhOH-support interaction and a corresponding ∼2-fold inhibition of the catalytic reaction, suggesting an active role of the PhOH-TiO2 hydrogen bond in catalysis. A comparison of the data measured here with the results previously reported for a Pd/CeO2 catalyst indicates that the efficiency of the Pd-supported catalysts is correlated to the amount of PhOH hydrogen bonded to the metal oxide support. Since CeO2 and TiO2 have similar ability to uptake activated hydrogen from a noble metal site, these data suggest that hydrogen spillover is the main mechanism by which Pd-activated hydrogens are shuttled to the PhOH adsorbed on the surface of the support. Consistent with this hypothesis, Pd supported on a non-reducible metal oxide (silica) displays negligible hydrogenation activity. Therefore, we conclude that basic and reducible metal oxides are active supports for the efficient hydrogenation of phenolic compounds due to their ability to hydrogen bond to the substrate and mediate the addition of the activated hydrogens to the adsorbed aromatic ring.
Collapse
Affiliation(s)
- Yeongseo An
- Department of Chemistry, Iowa State University Hach Hall, 2438 Pammel Drive Ames Iowa 50011 USA +1-515-294-7550 +1-515-294-1044
| | - Puranjan Chatterjee
- Department of Chemistry, Iowa State University Hach Hall, 2438 Pammel Drive Ames Iowa 50011 USA +1-515-294-7550 +1-515-294-1044
- Department of Energy, Ames Laboratory Ames Iowa 50011 USA
| | - Pranjali Naik
- Department of Chemistry, Iowa State University Hach Hall, 2438 Pammel Drive Ames Iowa 50011 USA +1-515-294-7550 +1-515-294-1044
- Department of Energy, Ames Laboratory Ames Iowa 50011 USA
| | - Sayak Banerjee
- Department of Chemistry, Iowa State University Hach Hall, 2438 Pammel Drive Ames Iowa 50011 USA +1-515-294-7550 +1-515-294-1044
| | - Wenyu Huang
- Department of Chemistry, Iowa State University Hach Hall, 2438 Pammel Drive Ames Iowa 50011 USA +1-515-294-7550 +1-515-294-1044
- Department of Energy, Ames Laboratory Ames Iowa 50011 USA
| | - Igor I Slowing
- Department of Chemistry, Iowa State University Hach Hall, 2438 Pammel Drive Ames Iowa 50011 USA +1-515-294-7550 +1-515-294-1044
- Department of Energy, Ames Laboratory Ames Iowa 50011 USA
| | - Vincenzo Venditti
- Department of Chemistry, Iowa State University Hach Hall, 2438 Pammel Drive Ames Iowa 50011 USA +1-515-294-7550 +1-515-294-1044
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University Ames Iowa 50011 USA
| |
Collapse
|
3
|
Huang M, Han Y, Xiang W, Wang C, Mao J, Zhou T, Wu X, Yu HQ. Catalytic Oxygen Activation over the Defective CuO Nanoparticles for Ultrafast Dehalogenation. ACS APPLIED MATERIALS & INTERFACES 2022; 14:29964-29973. [PMID: 35758015 DOI: 10.1021/acsami.2c08189] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The nucleophilic superoxide radical (O2•-)-based dehalogenation reaction shows great potential to degrade the toxic halogenated organic compounds (HOCs). But such an O2•--mediated reductive reaction often suffers from the competition of the secondary oxidative species (e.g., •OH), leading to inferior electron efficiency and possible disinfection byproduct formation. Here, an O2•--dominant ultrafast dehalogenation system is developed via molecular O2 activation by the oxygen vacancy (OV)-rich CuO nanoparticles (nCuO). The nCuO delivers a remarkable dechlorination rate constant of 3.92 × 10-2 L min-1 m-2 for 2,4-dichlorophenol, much higher than that of the conventional zerovalent (bi)metals. The absorbed O2 on the nCuO surface is exclusively responsible for O2•- generation, and its reactivity increases with the elevated OV content because of the enhanced orbital hybridization between the O p- and Cu d-orbitals. More importantly, the ubiquitous carbonate species firmly bound to the surface OVs block the formation of the secondary oxidative species via H2O2 activation, assuring the dominant role of the in situ generated O2•- for the selective HOC dehalogenation. The carbonate-deactivated OVs of the nCuO can be feasibly recovered via air annealing for sustainable dehalogenation. This work provides a new opportunity for selective O2•- generation via interfacial defect engineering for dehalogenation and other environmental applications.
Collapse
Affiliation(s)
- Mingjie Huang
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China
| | - Yi Han
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Wei Xiang
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
- Key Laboratory of Water and Wastewater Treatment (HUST), MOHURD, Wuhan 430074, China
| | - Chen Wang
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
- Key Laboratory of Water and Wastewater Treatment (HUST), MOHURD, Wuhan 430074, China
| | - Juan Mao
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
- Key Laboratory of Water and Wastewater Treatment (HUST), MOHURD, Wuhan 430074, China
| | - Tao Zhou
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Xiaohui Wu
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
- Key Laboratory of Water and Wastewater Treatment (HUST), MOHURD, Wuhan 430074, China
| | - Han-Qing Yu
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China
| |
Collapse
|
4
|
An Y, Sedinkin SL, Venditti V. Solution NMR methods for structural and thermodynamic investigation of nanoparticle adsorption equilibria. NANOSCALE ADVANCES 2022; 4:2583-2607. [PMID: 35769933 PMCID: PMC9195484 DOI: 10.1039/d2na00099g] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2022] [Accepted: 05/07/2022] [Indexed: 05/09/2023]
Abstract
Characterization of dynamic processes occurring at the nanoparticle (NP) surface is crucial for developing new and more efficient NP catalysts and materials. Thus, a vast amount of research has been dedicated to developing techniques to characterize sorption equilibria. Over recent years, solution NMR spectroscopy has emerged as a preferred tool for investigating ligand-NP interactions. Indeed, due to its ability to probe exchange dynamics over a wide range of timescales with atomic resolution, solution NMR can provide structural, kinetic, and thermodynamic information on sorption equilibria involving multiple adsorbed species and intermediate states. In this contribution, we review solution NMR methods for characterizing ligand-NP interactions, and provide examples of practical applications using these methods as standalone techniques. In addition, we illustrate how the integrated analysis of several NMR datasets was employed to elucidate the role played by support-substrate interactions in mediating the phenol hydrogenation reaction catalyzed by ceria-supported Pd nanoparticles.
Collapse
Affiliation(s)
- Yeongseo An
- Department of Chemistry, Iowa State University Hach Hall, 2438 Pammel Drive Ames Iowa 50011 USA +1-515-294-7550 +1-515-294-1044
| | - Sergey L Sedinkin
- Department of Chemistry, Iowa State University Hach Hall, 2438 Pammel Drive Ames Iowa 50011 USA +1-515-294-7550 +1-515-294-1044
| | - Vincenzo Venditti
- Department of Chemistry, Iowa State University Hach Hall, 2438 Pammel Drive Ames Iowa 50011 USA +1-515-294-7550 +1-515-294-1044
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University Ames Iowa 50011 USA
| |
Collapse
|