TY - JOUR

T1 - Effect of metal ratio in alumina-supported Pd-Rh nanoalloys on its performance in three way catalysis

AU - Vedyagin, Aleksey A.

AU - Stoyanovskii, Vladimir O.

AU - Plyusnin, Pavel E.

AU - Shubin, Yury V.

AU - Slavinskaya, Elena M.

AU - Mishakov, Ilya V.

PY - 2018/6/15

Y1 - 2018/6/15

N2 - The bimetallic Pd-Rh three-way catalysts were prepared by an incipient wetness impregnation of γ-Al2O3 with a joint solution of [Pd(NH3)4](NO3)2 and Na3 [Rh(NO2)6]. The ratio of the metals was varied by changing the ratio of the salt-precursors. The samples with Pd:Rh ratio of 3:2, 7:3 and 4:1 were compared in simultaneous oxidation of carbon monoxide, propane, propylene, and reduction of nitrogen monoxide at a lambda factor of 1.003 and 0.95. Stability tests were performed in a prompt thermal aging regime (consecutive heating-cooling cycles with a final temperature of 320, 600 and 800 °C). The samples were characterized by UV–vis and luminescence spectroscopies, and by testing reaction of ethane hydrogenolysis. It was found that the sample with Pd:Rh ratio of 3:2 is characterized with strong palladium-rhodium interaction, which makes this catalyst more stable at high temperature if compare with other alloyed Pd-Rh samples. Moreover, the mechanism of the three-way catalytic process over Pd:Rh (3:2) sample differs from other cases and involves a larger contribution of reactions with nitrogen oxide.

AB - The bimetallic Pd-Rh three-way catalysts were prepared by an incipient wetness impregnation of γ-Al2O3 with a joint solution of [Pd(NH3)4](NO3)2 and Na3 [Rh(NO2)6]. The ratio of the metals was varied by changing the ratio of the salt-precursors. The samples with Pd:Rh ratio of 3:2, 7:3 and 4:1 were compared in simultaneous oxidation of carbon monoxide, propane, propylene, and reduction of nitrogen monoxide at a lambda factor of 1.003 and 0.95. Stability tests were performed in a prompt thermal aging regime (consecutive heating-cooling cycles with a final temperature of 320, 600 and 800 °C). The samples were characterized by UV–vis and luminescence spectroscopies, and by testing reaction of ethane hydrogenolysis. It was found that the sample with Pd:Rh ratio of 3:2 is characterized with strong palladium-rhodium interaction, which makes this catalyst more stable at high temperature if compare with other alloyed Pd-Rh samples. Moreover, the mechanism of the three-way catalytic process over Pd:Rh (3:2) sample differs from other cases and involves a larger contribution of reactions with nitrogen oxide.

KW - Metal ratio

KW - Metastable Pd-Rh alloy

KW - Partly miscible metals

KW - Stability

KW - Three-way catalysts

KW - PALLADIUM

KW - RHODIUM

KW - 3-WAY CATALYSTS

KW - STABILITY

KW - OXYGEN STORAGE

KW - CO OXIDATION

KW - SOLID-SOLUTION

KW - CARBON-MONOXIDE

KW - C3H6 OXIDATION

KW - BIMETALLIC CATALYSTS

UR - http://www.scopus.com/inward/record.url?scp=85044605433&partnerID=8YFLogxK

U2 - 10.1016/j.jallcom.2018.03.250

DO - 10.1016/j.jallcom.2018.03.250

M3 - Article

AN - SCOPUS:85044605433

VL - 749

SP - 155

EP - 162

JO - Journal of Alloys and Compounds

JF - Journal of Alloys and Compounds

SN - 0925-8388

ER -