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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Cu-Modified SrTiO3 Perovskites Toward Enhanced Water-Gas Shift Catalysis: A Combined Experimental and Computational Study

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Author(s):
Coletta, Vitor C. [1] ; Goncalves, V, Renato ; Bernardi, Maria I. B. [2] ; Hanaor, Dorian A. H. [3] ; Assadi, M. Hussein N. [4] ; Marcos, Francielle C. F. [5] ; Nogueira, Francisco G. E. [6] ; Assaf, Elisabete M. [7] ; Mastelaro, Valmor R. [2]
Total Authors: 9
Affiliation:
[1] Univ Sao Paulo, Sao Carlos Inst Phys, BR-13566590 Sao Carlos, SP - Brazil
[2] Goncalves, Renato, V, Univ Sao Paulo, Sao Carlos Inst Phys, BR-13566590 Sao Carlos, SP - Brazil
[3] Tech Univ Berlin, Chair Adv Ceram Mat, D-10623 Berlin - Germany
[4] Natl Inst Mat Sci NIMS, Ctr Green Res Energy & Environm Mat, Tsukuba, Ibaraki 3050044 - Japan
[5] Univ Sao Paulo, Dept Chem Engn, Polytech Sch, BR-05508010 Sao Paulo, SP - Brazil
[6] Univ Fed Sao Carlos, Dept Chem Engn, BR-13565905 Sao Carlos, SP - Brazil
[7] Univ Sao Paulo, Sao Carlos Inst Chem, BR-13560970 Sao Carlos, SP - Brazil
Total Affiliations: 7
Document type: Journal article
Source: ACS APPLIED ENERGY MATERIALS; v. 4, n. 1, p. 452-461, JAN 25 2021.
Web of Science Citations: 0
Abstract

A water-gas shift reaction (WGS) is important and widely applied in the production of H-2. Cu-modified perovskites are promising catalysts for WGS reactions in hydrogen generation. However, the structure-dependent stability and reaction pathways of such materials remain unclear. Herein, we report catalytically active Cu-modified SrTiO3 (nominally SrTi1-xCuxO3) prepared by a modified polymeric precursor method. Microstructural analysis revealed a partially segregated CuO phase in the as-prepared materials. Operando X-ray diffraction and absorption spectroscopy showed the reduction of CuO into a stable metallic phase under conditions of WGS reactions for all compositions. Among the characterized materials, the x = 0.20 composition showed the highest turnover frequency, lowest activation energy, and the highest WGS rate at 300 degrees C. According to density functional calculations, the formation of CuO is energetically less favorable compared with SrTiO3, explaining why the segregated CuO phase on the SrTiO3 surface is reduced to Cu during the catalytic reaction, while SrTiO3 remains. For x = 0.20, the size of the segregated CuO phase is optimum for facilitating the catalytic reaction. In contrast, a higher Cu content (x = 0.3) results in an aggregation of smaller CuO particles, resulting in fewer surface active sites and a net decrease in catalytic performance. (AU)

FAPESP's process: 17/08293-8 - Project 14: direct synthesis of methanol from CO2
Grantee:Francielle Candian Firmino Marcos
Support Opportunities: Scholarships in Brazil - Post-Doctoral
FAPESP's process: 15/06246-7 - Biorefinery concept applied to biological wastewater treatment plants: environmental pollution control coupled with material and energy recovery
Grantee:Marcelo Zaiat
Support Opportunities: Research Projects - Thematic Grants
FAPESP's process: 13/07296-2 - CDMF - Center for the Development of Functional Materials
Grantee:Elson Longo da Silva
Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC