TY - JOUR
T1 - Operando NAP-XPS Observation and Kinetics Analysis of NO Reduction over Rh(111) Surface
T2 - Characterization of Active Surface and Reactive Species
AU - Ueda, Kohei
AU - Isegawa, Kazuhisa
AU - Amemiya, Kenta
AU - Mase, Kazuhiko
AU - Kondoh, Hiroshi
N1 - Funding Information:
We thank the Photon Factory staffs for their technical supports. This study was supported by the Grants-in-Aid for scientific research (Nos. 20245004 and 26248008). The experiments were performed under the approval of the Photon Factory Program Advisory Committee (PF PAC No. 2015S2-008). We would like to thank Shirahata N. and Masuda S. for the NAP-XPS measurements and the staffs of mechanical workshop of Keio University for fabricating sample holders and other relating metal parts.
Publisher Copyright:
© 2018 American Chemical Society.
PY - 2018/12/7
Y1 - 2018/12/7
N2 - NO reduction by CO on Rh(111) was investigated by near-ambient pressure X-ray photoelectron spectroscopy, mass spectrometry, and kinetic analysis. Under exposure to NO + CO mixed gases and with heating the surface from room temperature to 450 °C, NO dissociation and NO reduction reaction start simultaneously independent of gas pressure ratio of NO/CO, which indicates that NO dissociation triggers this reaction. From kinetic analyses based on observed adsorbate coverages under reaction conditions, the following two points are suggested: (i) NOhollow is a reactive species for N2 and N2O formation via N + NO reaction. (ii) At low temperatures, the N + NO reaction is dominant for N2 production, whereas above around 400 °C, the N + N reaction becomes dominant, which leads to an increase in N2 selectivity at the higher temperatures. Compared with the NO + CO reaction on Ir(111) surfaces, which exhibits a high N2 selectivity, the adsorption site of reactive NO and the availability of vacant surface sites could be key factors for the lower N2 selectivity for Rh(111).
AB - NO reduction by CO on Rh(111) was investigated by near-ambient pressure X-ray photoelectron spectroscopy, mass spectrometry, and kinetic analysis. Under exposure to NO + CO mixed gases and with heating the surface from room temperature to 450 °C, NO dissociation and NO reduction reaction start simultaneously independent of gas pressure ratio of NO/CO, which indicates that NO dissociation triggers this reaction. From kinetic analyses based on observed adsorbate coverages under reaction conditions, the following two points are suggested: (i) NOhollow is a reactive species for N2 and N2O formation via N + NO reaction. (ii) At low temperatures, the N + NO reaction is dominant for N2 production, whereas above around 400 °C, the N + N reaction becomes dominant, which leads to an increase in N2 selectivity at the higher temperatures. Compared with the NO + CO reaction on Ir(111) surfaces, which exhibits a high N2 selectivity, the adsorption site of reactive NO and the availability of vacant surface sites could be key factors for the lower N2 selectivity for Rh(111).
KW - NAP-XPS
KW - NO reduction
KW - Rh
KW - kinetics
KW - operando observation
KW - reaction mechanism
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U2 - 10.1021/acscatal.8b03180
DO - 10.1021/acscatal.8b03180
M3 - Article
AN - SCOPUS:85056500829
VL - 8
SP - 11663
EP - 11670
JO - ACS Catalysis
JF - ACS Catalysis
SN - 2155-5435
IS - 12
ER -