TY - JOUR
T1 - Oxidation and hydrogenation of Pd
T2 - Suppression of oxidation by prolonged H2 exposure
AU - Tamaoka, Takehiro
AU - Yoshida, Hideto
AU - Takeda, Seiji
N1 - Funding Information:
This works was supported in part by a Grant-in-Aid for Scientic Research (A), Grant No. 25246003 and “Dynamic Alliance for Open Innovation Bridging Human, Environment and Materials” from the Ministry of Education, Culture, Sports, Science and Technology of Japan (MEXT).
Publisher Copyright:
© 2019 The Royal Society of Chemistry.
PY - 2019
Y1 - 2019
N2 - We investigate the phase transition of a Pd surface in both oxidizing and reducing environments by environmental transmission electron microscopy (ETEM). ETEM allows us to study sequential exposure of Pd to O2 and H2 in the same TEM conditions. First, under ETEM observation, oxidation occurs at step edges but it can also occur at terraces. Second, as the most important result, we observed a novel process where previous exposure to H2 suppresses new oxidation of the Pd surface. Third, we show by electron energy loss spectroscopy (EELS) that this process, suppression of oxidation by previous exposure to H2, is not due to the formation of bulk β-phase Pd hydride. We also demonstrate that this process is not present in Pt. Finally, we discuss the hypothesis to explain this phenomenon: formation of surface-Pd-hydride suppresses the new oxidation. This observation, suppression of oxidation by H2 exposure, may eventually lead to new breakthroughs.
AB - We investigate the phase transition of a Pd surface in both oxidizing and reducing environments by environmental transmission electron microscopy (ETEM). ETEM allows us to study sequential exposure of Pd to O2 and H2 in the same TEM conditions. First, under ETEM observation, oxidation occurs at step edges but it can also occur at terraces. Second, as the most important result, we observed a novel process where previous exposure to H2 suppresses new oxidation of the Pd surface. Third, we show by electron energy loss spectroscopy (EELS) that this process, suppression of oxidation by previous exposure to H2, is not due to the formation of bulk β-phase Pd hydride. We also demonstrate that this process is not present in Pt. Finally, we discuss the hypothesis to explain this phenomenon: formation of surface-Pd-hydride suppresses the new oxidation. This observation, suppression of oxidation by H2 exposure, may eventually lead to new breakthroughs.
UR - http://www.scopus.com/inward/record.url?scp=85063332597&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85063332597&partnerID=8YFLogxK
U2 - 10.1039/c9ra00436j
DO - 10.1039/c9ra00436j
M3 - Article
AN - SCOPUS:85063332597
SN - 2046-2069
VL - 9
SP - 9113
EP - 9116
JO - RSC Advances
JF - RSC Advances
IS - 16
ER -