Investigation on Reduction Behaviors of SnO2 and SnO2-Supported CuO Sensor Materials by Temperature-Programmed Reduction Method Combined with Resistance Measurement

doi:10.18494/sam.2016.1410

Abstract

Highlights

CuO-doped SnO2 has been reported to be one of the potential materials for CO(1–3) sensors
The X-ray diffraction (XRD) results suggest that CuO is highly dispersed on SnO2 when the loading amount of CuO is smaller than 5 wt%, and the excess loading of copper forms bulk CuO, which can be reflected in the XRD pattern.(4) The crystalline sizes of SnO2 and CuO in CuO(x)/SnO2, which were estimated from SnO2(101) and CuO(002) XRD peaks using the Scherrer’s equation, are summarized in Table 1, being less dependent on the loading amount of CuO
The resistance measurement was combined with temperature-programmed reduction (TPR) measurement (TPR&R) to assign the reduction peaks in the TPR profiles of SnO2 and CuO(x)/SnO2

Summary

Introduction

CuO-doped SnO2 has been reported to be one of the potential materials for CO(1–3) sensors. It is well known that temperature-programmed reduction (TPR) measurement is one of the most powerful techniques for elucidating the reduction behavior of a material containing a noble metal, a transition metal oxide, or a lanthanide metal oxide. Numerous TPR studies on copper oxides have been reported, for example, CuO/CeO2,(4) CuO/TixSn1−xO2,(5) CuO/Al2O3,(6) Cu-Fe/Al2O3,(7) and K-Cu/Al2O3,(8) for clarifying the active copper site for CO oxidation,(4,5) water–gas shift reaction,(6,7) NOx reduction,(8) among others. Arino et al(9) reported that the TPR profile of SnO2 exhibited four reduction peaks at [250, 310, 420], and >470 °C and that the loading of Pt or Pd promoted the reduction of SnO2; that is, four reduction peaks shifted to a lower temperature by loading Pt or Pd on SnO2. A similar result was reported by Pavelko et al(10) The TPR profile of a metal oxide

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Discussion

Conclusion