Promotional Effects on the Catalytic Activity of Co-Fe Alloy Supported on Graphitic Carbon for CO2 Hydrogenation

Bogdan Jurca; Lu Peng; Ana Primo; Alvaro Gordillo; Amarajothi Dhakshinamoorthy; Vasile I Parvulescu; Hermenegildo García

doi:10.3390/nano12183220

Promotional Effects on the Catalytic Activity of Co-Fe Alloy Supported on Graphitic Carbon for CO₂ Hydrogenation

Nanomaterials (Basel). 2022 Sep 16;12(18):3220. doi: 10.3390/nano12183220.

Authors

Bogdan Jurca¹, Lu Peng², Ana Primo², Alvaro Gordillo³, Amarajothi Dhakshinamoorthy^{4

5}, Vasile I Parvulescu¹, Hermenegildo García²

Affiliations

¹ Department of Organic Chemistry and Biochemistry and Catalysis, Faculty of Chemistry, University of Bucharest, Bdul Regina Elisabeta 4-12, 030016 Bucharest, Romania.
² Instituto Universitario de Tecnología Química, Universitat Politècnica de València-Consejo Superior de Investigaciones Científicas, Av. De los Naranjos s/n, 46022 Valencia, Spain.
³ BASF SE, 67056 Ludwigshafen am Rhein, Germany.
⁴ Departamento de Química, Universitat Politècnica de València, Av. De los Naranjos s/n, 46022 Valencia, Spain.
⁵ School of Chemistry, Madurai Kamaraj University, Madurai 625021, Tamil Nadu, India.

Abstract

Starting from the reported activity of Co-Fe nanoparticles wrapped onto graphitic carbon (Co-Fe@C) as CO₂ hydrogenation catalysts, the present article studies the influence of a series of metallic (Pd, Ce, Ca, Ca, and Ce) and non-metallic (S in various percentages and S and alkali metals) elements as Co-Fe@C promoters. Pd at 0.5 wt % somewhat enhances CO₂ conversion and CH₄ selectivity, probably due to H₂ activation and spillover on Co-Fe. At similar concentrations, Ce does not influence CO₂ conversion but does diminish CO selectivity. A 25 wt % Fe excess increases the Fe-Co particle size and has a detrimental effect due to this large particle size. The presence of 25 wt % of Ca increases the CO₂ conversion and CH₄ selectivity remarkably, the effect being attributable to the CO₂ adsorption capacity and basicity of Ca. Sulfur at a concentration of 2.1% or higher acts as a strong poison, decreasing CO₂ conversion and shifting selectivity to CO. The combination of S and alkali metals as promoters maintain the CO selectivity of S but notably increase the CO₂ conversion. Overall, this study shows how promoters and poisons can alter the catalytic activity of Co/Fe@C catalysts, changing from CH₄ to CO. It is expected that further modulation of the activity of Co/Fe@C catalysts can serve to drive the activity and selectivity of these materials to any CO₂ hydrogenation products that are wanted.

Keywords: CO2 methanation; alloy nanoparticles; graphitic carbon.

Grants and funding

This research was funded by the Spanish Ministry of Science and Innovation and the University (Severo Ochoa SEV2021 and RTI2018.98237-B-CO1) and Generalitat Valenciana (Prometeo 2017/083). A.P. is the recipient of a Ramón y Cajal research associate contract awarded by the Spanish Ministry of Science and Innovation. L.P. thanks the Generalitat Valenciana for a Santiago Grisolía scholarship. BASF is thanked for financial support.