1
|
Zhou LL, Li SQ, Ma C, Fu XP, Xu YS, Wang WW, Dong H, Jia CJ, Wang FR, Yan CH. Promoting Molecular Exchange on Rare-Earth Oxycarbonate Surfaces to Catalyze the Water-Gas Shift Reaction. J Am Chem Soc 2023; 145:2252-2263. [PMID: 36657461 PMCID: PMC9896556 DOI: 10.1021/jacs.2c10326] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
It is highly desirable to fabricate an accessible catalyst surface that can efficiently activate reactants and desorb products to promote the local surface reaction equilibrium in heterogeneous catalysis. Herein, rare-earth oxycarbonates (Ln2O2CO3, where Ln = La and Sm), which have molecular-exchangeable (H2O and CO2) surface structures according to the ordered layered arrangement of Ln2O22+ and CO32- ions, are unearthed. On this basis, a series of Ln2O2CO3-supported Cu catalysts are prepared through the deposition precipitation method, which provides excellent catalytic activity and stability for the water-gas shift (WGS) reaction. Density functional theory calculations combined with systematic experimental characterizations verify that H2O spontaneously dissociates on the surface of Ln2O2CO3 to form hydroxyl by eliminating the carbonate through the release of CO2. This interchange efficiently promotes the WGS reaction equilibrium shift on the local surface and prevents the carbonate accumulation from hindering the active sites. The discovery of the unique layered structure provides a so-called "self-cleaning" active surface for the WGS reaction and opens new perspectives about the application of rare-earth oxycarbonate nanomaterials in C1 chemistry.
Collapse
Affiliation(s)
- Lu-Lu Zhou
- Key
Laboratory for Colloid and Interface Chemistry, Key Laboratory of
Special Aggregated Materials, School of Chemistry and Chemical Engineering, Shandong University, Jinan250100, China
| | - Shan-Qing Li
- School
of Materials and Environmental Engineering, Chizhou University, Chizhou247000, China
| | - Chao Ma
- College
of Materials Science and Engineering, Hunan
University, Changsha410082, China
| | - Xin-Pu Fu
- Key
Laboratory for Colloid and Interface Chemistry, Key Laboratory of
Special Aggregated Materials, School of Chemistry and Chemical Engineering, Shandong University, Jinan250100, China
| | - Yi-Shuang Xu
- Key
Laboratory for Colloid and Interface Chemistry, Key Laboratory of
Special Aggregated Materials, School of Chemistry and Chemical Engineering, Shandong University, Jinan250100, China
| | - Wei-Wei Wang
- Key
Laboratory for Colloid and Interface Chemistry, Key Laboratory of
Special Aggregated Materials, School of Chemistry and Chemical Engineering, Shandong University, Jinan250100, China
| | - Hao Dong
- Beijing
National Laboratory for Molecular Sciences, State Key Lab of Rare
Earth Materials Chemistry and Applications, PKU-HKU Joint Lab in Rare
Earth Materials and Bioinorganic Chemistry, Peking University, Beijing100871, China
| | - Chun-Jiang Jia
- Key
Laboratory for Colloid and Interface Chemistry, Key Laboratory of
Special Aggregated Materials, School of Chemistry and Chemical Engineering, Shandong University, Jinan250100, China,
| | - Feng Ryan Wang
- Department
of Chemical Engineering, University College
London, LondonWC1E 7JE, U.K.,
| | - Chun-Hua Yan
- Beijing
National Laboratory for Molecular Sciences, State Key Lab of Rare
Earth Materials Chemistry and Applications, PKU-HKU Joint Lab in Rare
Earth Materials and Bioinorganic Chemistry, Peking University, Beijing100871, China,
| |
Collapse
|
3
|
Abstract
CO2 methanation is a promising reaction for utilizing CO2 using hydrogen generated by renewable energy. In this study, CO and CO2 methanation were examined over ceria-supported cobalt catalysts with low cobalt contents. The catalysts were prepared using a wet impregnation and co-precipitation method and pretreated at different temperatures. These preparation variables affected the catalytic performance as well as the physicochemical properties. These properties were characterized using various techniques including N2 physisorption, X-ray diffraction, H2 chemisorption, temperature-programmed reduction with H2, and temperature-programmed desorption after CO2 chemisorption. Among the prepared catalysts, the ceria-supported cobalt catalyst that was prepared using a wet impregnation method calcined in air at 500 °C, and reduced in H2 at 500 °C, showed the best catalytic performance. It is closely related to the large catalytically active surface area, large surface area, and large number of basic sites. The in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) study revealed the presence of carbonate, bicarbonate, formate, and CO on metallic cobalt.
Collapse
|
4
|
Martinelli M, Garcia R, Watson CD, Cronauer DC, Kropf AJ, Jacobs G. Promoting the Selectivity of Pt/m-ZrO 2 Ethanol Steam Reforming Catalysts with K and Rb Dopants. NANOMATERIALS 2021; 11:nano11092233. [PMID: 34578548 PMCID: PMC8468407 DOI: 10.3390/nano11092233] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 08/25/2021] [Accepted: 08/25/2021] [Indexed: 11/16/2022]
Abstract
The ethanol steam reforming reaction (ESR) was investigated on unpromoted and potassium- and rubidium-promoted monoclinic zirconia-supported platinum (Pt/m-ZrO2) catalysts. Evidence from in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) characterization indicates that ethanol dissociates to ethoxy species, which undergo oxidative dehydrogenation to acetate followed by acetate decomposition. The acetate decomposition pathway depends on catalyst composition. The decarboxylation pathway tends to produce higher overall hydrogen selectivity and is the most favored route at high alkali loading (2.55 wt.% K and higher or 4.25 wt.% Rb and higher). On the other hand, decarbonylation is a significant route for the undoped catalyst or when a low alkali loading (e.g., 0.85% K or 0.93% Rb) is used, thus lowering the overall H2 selectivity of the process. Results of in situ DRIFTS and the temperature-programmed reaction of ESR show that alkali doping promotes forward acetate decomposition while exposed metallic sites tend to facilitate decarbonylation. In previous work, 1.8 wt.% Na was found to hinder decarbonylation completely. Due to the fact that 1.8 wt.% Na is atomically equivalent to 3.1 wt.% K and 6.7 wt.% Rb, the results show that less K (2.55% K) or Rb (4.25% Rb) is needed to suppress decarbonylation; that is, more basic cations are more efficient promoters for improving the overall hydrogen selectivity of the ESR process.
Collapse
Affiliation(s)
- Michela Martinelli
- Center for Applied Energy Research, University of Kentucky, 2540 Research Park Drive, Lexington, KY 40511, USA;
| | - Richard Garcia
- Department of Biomedical Engineering and Chemical Engineering, The University of Texas at San Antonio, 1 UTSA Circle, San Antonio, TX 78249, USA; (R.G.); (C.D.W.)
| | - Caleb D. Watson
- Department of Biomedical Engineering and Chemical Engineering, The University of Texas at San Antonio, 1 UTSA Circle, San Antonio, TX 78249, USA; (R.G.); (C.D.W.)
| | | | - A. Jeremy Kropf
- Argonne National Laboratory, Lemont, IL 60439, USA; (D.C.C.); (A.J.K.)
| | - Gary Jacobs
- Department of Biomedical Engineering and Chemical Engineering, The University of Texas at San Antonio, 1 UTSA Circle, San Antonio, TX 78249, USA; (R.G.); (C.D.W.)
- Department of Mechanical Engineering, The University of Texas at San Antonio, 1 UTSA Circle, San Antonio, TX 78249, USA
- Correspondence: ; Tel.: +1-210-458-7080
| |
Collapse
|