TY - JOUR
T1 - Unraveling the H2 promotional effect on the Palladium catalysed CO oxidation using a combination of temporally and spatially resolved investigations
AU - Stewart, Caomhan
AU - Gibson, Emma K
AU - Morgan, Kevin
AU - Cibin, Giannantonio
AU - Dent, Andrew
AU - Hardacre, Christopher
AU - Kondratenko, Evgenii V.
AU - Kondratenko, Vita
AU - McManus, Colin
AU - Rogers, Scott
AU - Stere, Cristina-Elena
AU - Chansai, Sarayute
AU - Wang, Yi-Chi
AU - Haigh, Sarah
AU - Wells, Peter
AU - Goguet, Alexandre
PY - 2018/9/7
Y1 - 2018/9/7
N2 - The promotional effect of H2 on the oxidation of CO is of topical interest and there is debate over whether this promotion is due to either thermal or chemical effects. As yet there is no definitive consensus in the literature. Combining spatially resolved mass spectrometry and X-ray absorption spectroscopy (XAS) we observe a specific environment of the active catalyst during CO oxidation, having the same specific local coordination of the Pd in both the absence and presence of H2. In combination with Temporal Analysis of Products (TAP), performed under isothermal conditions, a mechanistic insight into the promotional effect of H2 was found, providing clear evidence of non-thermal effects in the hydrogen promoted of oxidation of carbon monoxide. We have identified that H2 promotes the Langmuir Hinshelwood mechanism and we propose this is linked to the increased interaction of O with the Pd surface in the presence of H2. This combination of spatially resolved MS and XAS and TAP studies has provided previously unobserved insights into the nature of this promotional effect.
AB - The promotional effect of H2 on the oxidation of CO is of topical interest and there is debate over whether this promotion is due to either thermal or chemical effects. As yet there is no definitive consensus in the literature. Combining spatially resolved mass spectrometry and X-ray absorption spectroscopy (XAS) we observe a specific environment of the active catalyst during CO oxidation, having the same specific local coordination of the Pd in both the absence and presence of H2. In combination with Temporal Analysis of Products (TAP), performed under isothermal conditions, a mechanistic insight into the promotional effect of H2 was found, providing clear evidence of non-thermal effects in the hydrogen promoted of oxidation of carbon monoxide. We have identified that H2 promotes the Langmuir Hinshelwood mechanism and we propose this is linked to the increased interaction of O with the Pd surface in the presence of H2. This combination of spatially resolved MS and XAS and TAP studies has provided previously unobserved insights into the nature of this promotional effect.
UR - https://pubs.acs.org/doi/abs/10.1021/acscatal.8b01509
U2 - 10.1021/acscatal.8b01509
DO - 10.1021/acscatal.8b01509
M3 - Article
SN - 2155-5435
SP - 8255
EP - 8262
JO - ACS Catalysis
JF - ACS Catalysis
ER -