Mixed Ni-Co sub-stoichiometric spinels as catalytic precursors for dry reforming of methane
Eight mixed Ni-Co spinels with (Ni+Co)/Al molar ratios between 0.05 and 0.50 were synthesised by co-precipitation to serve as precursors for bimetallic Ni-Co catalysts for the dry reforming of methane reaction. Both calcined and reduced samples were examined by BET measurements, X-Ray diffraction, R...
| Authors: | , , , , |
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| Format: | article |
| Publication Date: | 2025 |
| Country: | España |
| Institution: | Universidad del País Vasco |
| Repository: | Addi. Archivo Digital para la Docencia y la Investigación |
| OAI Identifier: | oai:dnet:addi________::108e3410304b97998182af4444e171fd |
| Online Access: | http://hdl.handle.net/10810/78692 |
| Access Level: | Open access |
| Keyword: | Mixed spinel Ni-Co alloy Methane dry reforming Syngas |
| Summary: | Eight mixed Ni-Co spinels with (Ni+Co)/Al molar ratios between 0.05 and 0.50 were synthesised by co-precipitation to serve as precursors for bimetallic Ni-Co catalysts for the dry reforming of methane reaction. Both calcined and reduced samples were examined by BET measurements, X-Ray diffraction, Raman spectroscopy, XPS spectroscopy, STEM/HAADF, STEM/EDS elemental mapping, temperature-programmed reduction with H2, temperature-programmed surface reaction with CH4, temperature-programmed desorption of CO2, thermogravimetric analysis and TEM, and their catalytic activity was studied for the dry reforming of methane at 650 °C at 80 L g-1 h-1. All the precursors synthesised with (Ni+Co)/Al molar ratios below 0.25 presented a high degree of spinel formation without the presence of segregated oxides. On the other hand, all the reduced catalysts presented a comparable structure, with crystallites of sizes between 20 and 30 nm composed of a homogeneous Ni-Co alloy, with the absence of isolated metals. The catalyst based on the spinelic precursor with a (Ni+Co)/Al molar ratio of 0.15 resulted the most active and selective towards H2 formation, achieving CH4 conversion values of 93 % after 24 h of time on stream and yielding a syngas with a H2/CO molar ratio of 1.1. Despite significant formation of carbonaceous deposits, this optimum sample was still able to operate efficiently for 200 h. |
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