Ceria Promoted Cu-Ni/SiO2 Catalyst for Selective Hydrodeoxygenation of Vanillin

Deboshree Mukherjee; Ramana Singuru; Perala Venkataswamy; Devaiah Damma; Benjaram M Reddy

doi:10.1021/acsomega.9b00039

Ceria Promoted Cu-Ni/SiO₂ Catalyst for Selective Hydrodeoxygenation of Vanillin

ACS Omega. 2019 Mar 4;4(3):4770-4778. doi: 10.1021/acsomega.9b00039. eCollection 2019 Mar 31.

Authors

Deboshree Mukherjee^{1

1}, Ramana Singuru^{1

1}, Perala Venkataswamy², Devaiah Damma³, Benjaram M Reddy¹

Affiliations

¹ Catalysis and Fine Chemicals Department and Academy of Scientific and Innovative Research, CSIR - Indian Institute of Chemical Technology, Uppal Road, Hyderabad - 500 007, India.
² Department of Chemistry, Osmania University, Hyderabad - 500 007, India.
³ Chemical Engineering, College of Engineering and Applied Science, University of Cincinnati, Cincinnati, Ohio 45221-0012, United States.

Abstract

A ceria (CeO₂) promoted Cu-Ni bimetallic catalyst supported on SiO₂ (Cu-Ni/CeO₂-SiO₂) was prepared and evaluated for catalytic hydrodeoxygenation (HDO) of vanillin. Silica supported monometallic Cu and Ni catalysts and bimetallic Cu-Ni catalyst (Cu/SiO₂, Ni/SiO₂, and Cu-Ni/SiO₂), without a ceria promoter, were also synthesized and tested for the same application. The highest conversion of vanillin was achieved with the Cu-Ni/CeO₂-SiO₂ catalyst. Vanillyl alcohol was the sole product in the initial 2 h, followed by the formation of 2-methoxy-4-methylphenol, which was observed. Characterization of the synthesized catalysts revealed the presence of overlapping crystalline phases of CuO, NiO, and CeO₂ on the Cu-Ni/CeO₂-SiO₂ surface. We extended our study to find out the results of using CeO₂ as the support of the Cu-Ni bimetallic catalyst (Cu-Ni/CeO₂). Partial incorporation of Cu and Ni cations into the ceria lattice took place, leading to the decrease of specific surface area and a concomitant compromise in the conversion. In the case of the Cu-Ni/CeO₂-SiO₂ catalyst, the higher conversion was accredited to the facile formation of Cu⁺ active centers by the synergistic interaction between Ce⁺⁴/Ce⁺³ and Cu⁺²/Cu⁺ redox couples and the incorporation of oxygen vacancies on the catalyst surface.