TY - JOUR
T1 - Physicochemical characterization of highly dispersed platinum and chromium on zeolite beta
AU - Izutsu, Yoshiyuki
AU - Oku, Yuki
AU - Hidaka, Yusuke
AU - Kanaya, Naoki
AU - Nakajima, Yoshiki
AU - Fukuroi, Jun
AU - Yoshida, Kaname
AU - Sasaki, Yukichi
AU - Sekine, Yasushi
AU - Matsukata, Masahiko
PY - 2014/5/22
Y1 - 2014/5/22
N2 - Structures of platinum and chromium supported on zeolite beta were investigated by XAFS, XPS, UV-vis, NH3-TPD, XRD, CO chemisorption, and molecular dynamics simulation. Both platinum and chromium were uniformly dispersed in the micropore of zeolite beta. Loading of chromium helped platinum to disperse highly and stabilized in the micropore of beta. Major species of platinum on PtCr/beta after calcination at 773 K was Pt2+ forming a Pt-O bond. The Pt-O bond disappeared, and a Pt-Pt bond did not appear by reducing PtCr/beta in hydrogen, accompanying formation of Pt0. Chromium was loaded as chromate anion in the micropore of zeolite. Results of molecular dynamics simulation showed that Pt2+ associated with CrO42- in the micropore of zeolite beta was more stable than those in the absence of chromium species. We concluded that CrO 42- electrostatically stabilizes Pt2+ and inhibits migration and aggregation of platinum.
AB - Structures of platinum and chromium supported on zeolite beta were investigated by XAFS, XPS, UV-vis, NH3-TPD, XRD, CO chemisorption, and molecular dynamics simulation. Both platinum and chromium were uniformly dispersed in the micropore of zeolite beta. Loading of chromium helped platinum to disperse highly and stabilized in the micropore of beta. Major species of platinum on PtCr/beta after calcination at 773 K was Pt2+ forming a Pt-O bond. The Pt-O bond disappeared, and a Pt-Pt bond did not appear by reducing PtCr/beta in hydrogen, accompanying formation of Pt0. Chromium was loaded as chromate anion in the micropore of zeolite. Results of molecular dynamics simulation showed that Pt2+ associated with CrO42- in the micropore of zeolite beta was more stable than those in the absence of chromium species. We concluded that CrO 42- electrostatically stabilizes Pt2+ and inhibits migration and aggregation of platinum.
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U2 - 10.1021/jp500232s
DO - 10.1021/jp500232s
M3 - Article
AN - SCOPUS:84901366128
SN - 1932-7447
VL - 118
SP - 10746
EP - 10753
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
IS - 20
ER -