Optimizing Pd:Zn molar Ratio in PdZn/CeO2 for CO2 Hydrogenation to Methanol
Name:
Ojelade et al.pdf
Size:
1.726Mb
Format:
PDF
Description:
Accepted manuscript
Embargo End Date:
2021-07-30
Type
ArticleAuthors
Ojelade, Opeyemi A.Zaman, Sharif F.

Daous, Muhammad A.
Al-Zahrani, Abdulrahim A.
Malik, Ali S.

Driss, Hafedh
Shterk, Genrikh

Gascon, Jorge

KAUST Department
Advanced Catalytic Materials, KAUST Catalysis Center (KCC), King Abdullah University of Science and Technology, Thuwal, 23955, Saudi ArabiaChemical Engineering Program
KAUST Catalysis Center (KCC)
Physical Science and Engineering (PSE) Division
KAUST Grant Number
JP-19-001Date
2019-07-30Online Publication Date
2019-07-30Print Publication Date
2019-07Embargo End Date
2021-07-30Permanent link to this record
http://hdl.handle.net/10754/656511
Metadata
Show full item recordAbstract
We report the compositional optimization of Pd:Zn/CeO2 catalysts prepared via sol-gel chelatization for the hydrogenation of CO2 under mild reaction conditions. The formation of a PdZn alloy, which is the main active phase for this reaction, was maximized for the catalyst with a Pd to Zn ratio close to 1. For this catalyst, a maximum conversion of 14%, close to thermodynamic equilibrium, and high selectivity to methanol (95%) were achieved at 220 °C, 20 bar, 2400 h−1 GHSV and H2:CO2 stoichiometric ratio of 3:1. The formation of PdZn alloys was achieved by reducing the catalyst precursor at 550 °C under hydrogen flow and confirmed by XRD. XPS study confirmed the presence of Pd°, being maximum for the optimized catalyst composition. At lower temperature, i.e. 180 °C, 1.0PdZn catalyst showed 100% selectivity to methanol with 8% CO2 conversion. RWGS reaction is responsible for the production of CO and its selectivity increases with temperature. In situ DRIFTS suggests that CO2 is activated as adsorbed CO3- species over CeO2. Surface micro-kinetics demonstrates that methanol can be formed either via formaldehyde or formic acid surface intermediates.Citation
Ojelade, O. A., Zaman, S. F., Daous, M. A., Al-Zahrani, A. A., Malik, A. S., Driss, H., … Gascon, J. (2019). Optimizing Pd:Zn molar Ratio in PdZn/CeO2 for CO2 Hydrogenation to Methanol. Applied Catalysis A: General, 117185. doi:10.1016/j.apcata.2019.117185Sponsors
This joint project was co-founded by King Abdulaziz University (KAU), Jeddah, and King Abdullah University of Science and Technology (KAUST), Thuwal, under grant number “JP-19-001”. The authors, therefore, acknowledge KAU and KAUST for their technical and financial support.Publisher
Elsevier BVJournal
Applied Catalysis A: GeneralAdditional Links
https://linkinghub.elsevier.com/retrieve/pii/S0926860X19303400ae974a485f413a2113503eed53cd6c53
10.1016/j.apcata.2019.117185