TY - JOUR
T1 - Chasing PtOx species in ceria supported platinum during CO oxidation extinction with correlative operando spectroscopic techniques
AU - Di, Mengqiao
AU - Simmance, Kerry
AU - Schaefer, Andreas
AU - Feng, Yanyue
AU - Hemmingsson, Felix
AU - Skoglundh, Magnus
AU - Bell, Tamsin
AU - Thompsett, David
AU - Ajakaiye Jensen, Lucy Idowu
AU - Blomberg, Sara
AU - Carlsson, Per Anders
PY - 2022/5
Y1 - 2022/5
N2 - Industrially relevant, highly dispersed, Pt/ceria and reference Pt/alumina catalysts with narrow Pt particle size distributions have been prepared, characterised ex situ and studied for CO oxidation by operando infrared and X-ray absorption spectroscopy. At high CO conversions, spectator CO ad-species on ionic platinum are observed while the CO oxidation proceeds on Pt particles in a high oxidation state exhibiting significant Pt[sbnd]O coordination. During the protracted catalytic extinction, the CO coverage builds up gradually while the Pt oxidation state and Pt[sbnd]O coordination remain high because of interactions with ceria. The observed CO oxidation at high CO coverage is suggested to involve sites at the platinum-ceria boundary that cannot be CO self-poisoned. This behaviour is in stark contrast to that of Pt/alumina, which shows removal of platinum oxides formed during CO oxidation and the classical drop in catalytic activity caused by rapid CO self-poisoning when reaching a critical temperature.
AB - Industrially relevant, highly dispersed, Pt/ceria and reference Pt/alumina catalysts with narrow Pt particle size distributions have been prepared, characterised ex situ and studied for CO oxidation by operando infrared and X-ray absorption spectroscopy. At high CO conversions, spectator CO ad-species on ionic platinum are observed while the CO oxidation proceeds on Pt particles in a high oxidation state exhibiting significant Pt[sbnd]O coordination. During the protracted catalytic extinction, the CO coverage builds up gradually while the Pt oxidation state and Pt[sbnd]O coordination remain high because of interactions with ceria. The observed CO oxidation at high CO coverage is suggested to involve sites at the platinum-ceria boundary that cannot be CO self-poisoned. This behaviour is in stark contrast to that of Pt/alumina, which shows removal of platinum oxides formed during CO oxidation and the classical drop in catalytic activity caused by rapid CO self-poisoning when reaching a critical temperature.
KW - CO self-poisoning
KW - Infrared spectroscopy
KW - Interfacial reaction
KW - Low-temperature activity
KW - Nanoparticles
KW - Platinum oxides
KW - X-ray absorption spectroscopy
U2 - 10.1016/j.jcat.2022.03.022
DO - 10.1016/j.jcat.2022.03.022
M3 - Article
AN - SCOPUS:85127315088
VL - 409
SP - 1
EP - 11
JO - Journal of Catalysis
JF - Journal of Catalysis
SN - 1090-2694
ER -