Evidence of Alloy Formation during the Activation of Graphite-Supported Palladium-Cobalt Catalysts

• Published in: Journal of catalysis Vol. 186; no. 1; pp. 20 - 30
• Main Authors: Noronha, F.B., Schmal, M., Fréty, R., Bergeret, G., Moraweck, B.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Inc 15-08-1999; Elsevier
• Subjects: Catalysis; Catalysts: preparations and properties; Chemical Sciences; Chemistry; Exact sciences and technology; General and physical chemistry; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; magnetization; bimetallic; catalysts; palladium; cobalt; graphite; in situ XRD; EXAFS; alloy formation; Mixed catalyst; Transition metal; Palladium; Experimental study; Cobalt; X ray diffraction; Hydrogenation; Butadiene; Supported catalyst; EXAFS spectrometry; Heterogeneous catalysis; Transition metal Alloys; Graphite; Platinoid; Magnetic properties
• ISSN: 0021-9517; 1090-2694
• DOI: 10.1006/jcat.1999.2461

Magnetism, XRD, and EXAFS analyses were used to study the formation of a solid solution on Pd-Co/G catalysts during reduction treatment. After reduction at 773 K, magnetic measurements revealed the formation of a Pd-Co alloy. XRD analysis in situ allowed us to follow the alloy process during the increase of the reduction temperature. The XRD results showed the presence of a heterogeneous solid solution after reduction at 773 K. Pd and Co K-edge EXAFS analysis confirmed that bimetallic particles with a palladium- and cobalt-rich phase were formed. The formation of a solid solution decreased the adsorption strength of 1,3-butadiene on new Pd sites modified by Co.