In situ study of copper reduction in SrTi1−xCuxO3 nanoparticles. Issue 3 (21st December 2015)

• Record Type: Journal Article
• Authors: Coletta, Vitor C.; Marcos, Francielle C. F.; Nogueira, Francisco G. E.; Bernardi, Maria I. B.; Michalowicz, Alain; Gonçalves, Renato V.; Assaf, Elisabete M.; Mastelaro, Valmor R.
• Is Part Of: Physical chemistry chemical physics. Volume 18:Issue 3(2016)
• Page Start: 2070
• Page End: 2079
• Publication Date: 2015-12-21
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/c5cp05939a
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : Fourier transform magnitude of Cu K-edge absorption spectra before (300 K) and after (550 K) reduction. Abstract : Perovskite strontium titanate is a promising functional material for gas sensors and catalysis applications. Herein, we report the preparation of SrTi1− x Cu x O3 nanoparticles with Cu doped in the B sites using a modified polymeric precursor method. This study describes in detail the structural and local atomic configurations for the substitution of Cu into the titanium sites and its reducibility using X-ray diffraction (XRD), field emission gun scanning and transmission electron microscopies (FEG-SEM and TEM), X-ray absorption spectroscopy (XAS), X-ray photoelectron spectroscopy (XPS) and temperature-programmed reduction (TPR) analyses. Our results indicate that copper is segregated for x ≥ 0.06. After exposing the samples to a hydrogen-rich atmosphere at temperatures over 500 K, copper is reduced from Cu 2+ to metallic Cu. This reduction was attributed to copper atoms that originated primarily from the CuO phase.