TY - JOUR

T1 - Boosting the activity of PdAg2/Al2O3 supported catalysts towards the selective acetylene hydrogenation by means of CO-induced segregation

T2 - A combined NAP XPS and mass-spectrometry study

AU - Bukhtiyarov, A. V.

AU - Panafidin, M. A.

AU - Prosvirin, I. P.

AU - Mashkovsky, I. S.

AU - Markov, P. V.

AU - Rassolov, A. V.

AU - Smirnova, N. S.

AU - Baeva, G. N.

AU - Rameshan, Christoph

AU - Rameshan, Raffael

AU - Zubavichus, Y. V.

AU - Bukhtiyarov, V. I.

AU - Stakheev, A. Yu

N1 - Publisher Copyright: © 2022 Elsevier B.V.

PY - 2022/12/1

Y1 - 2022/12/1

N2 - Selective hydrogenation (or semi-hydrogenation) of acetylene into ethylene is an important industrial process. The aim of the present work is thus to learn regularities governing the CO-induced segregation and elaborate practical procedures for tuning the surface structure of Pd-Ag nanoparticles to improve their catalytic performance towards the selective hydrogenation of acetylene to ethylene. Utilizing NAP XPS the CO adsorption-induced Pd atoms segregation in supported PdAg2/Al2O3 catalysts already at room temperature has been shown. The surface enrichment with Pd further increases if the treatment temperature is increased up to 250 °C. This specific configuration with a redistributed Pd/Ag surface atomic ratio is appreciably stable and self-sustained even at the absence of CO at moderately elevated temperatures. Nevertheless, a reductive treatment in hydrogen at 450 °C reverts the nanoparticle surface structure to the pristine state. Catalytic properties of this peculiar CO-induced configuration of PdAg2/Al2O3 towards the selective acetylene hydrogenation was investigated using a combination of NAP XPS and MS techniques. The PdAg2/Al2O3 catalyst with the surface enriched with Pd due to the CO-induced segregation manifests improved activity with 100 % selectivity under the conditions used. The results obtained clearly demonstrate that CO adsorption-induced segregation is a powerful tool that can be used to optimize the surface composition and catalytic performance of bimetallic nanoparticles.

AB - Selective hydrogenation (or semi-hydrogenation) of acetylene into ethylene is an important industrial process. The aim of the present work is thus to learn regularities governing the CO-induced segregation and elaborate practical procedures for tuning the surface structure of Pd-Ag nanoparticles to improve their catalytic performance towards the selective hydrogenation of acetylene to ethylene. Utilizing NAP XPS the CO adsorption-induced Pd atoms segregation in supported PdAg2/Al2O3 catalysts already at room temperature has been shown. The surface enrichment with Pd further increases if the treatment temperature is increased up to 250 °C. This specific configuration with a redistributed Pd/Ag surface atomic ratio is appreciably stable and self-sustained even at the absence of CO at moderately elevated temperatures. Nevertheless, a reductive treatment in hydrogen at 450 °C reverts the nanoparticle surface structure to the pristine state. Catalytic properties of this peculiar CO-induced configuration of PdAg2/Al2O3 towards the selective acetylene hydrogenation was investigated using a combination of NAP XPS and MS techniques. The PdAg2/Al2O3 catalyst with the surface enriched with Pd due to the CO-induced segregation manifests improved activity with 100 % selectivity under the conditions used. The results obtained clearly demonstrate that CO adsorption-induced segregation is a powerful tool that can be used to optimize the surface composition and catalytic performance of bimetallic nanoparticles.

KW - Acetylene hydrogenation

KW - CO adsorption-induced segregation

KW - In situ measurements

KW - Near-ambient pressure X-ray photoelectron spectroscopy

KW - Pd-Ag bimetallic catalysts

UR - http://www.scopus.com/inward/record.url?scp=85135793038&partnerID=8YFLogxK

U2 - 10.1016/j.apsusc.2022.154497

DO - 10.1016/j.apsusc.2022.154497

M3 - Article

AN - SCOPUS:85135793038

VL - 604.2022

JO - Applied surface science

JF - Applied surface science

SN - 0169-4332

IS - 1 December

M1 - 154497

ER -