Assessing the impact of textural properties in Ni-Fe catalysts for CO2 methanation performance

In heterogeneous catalysis, the benefits of employing adequate textural properties on the catalytic performances are usually stated. Nevertheless, the quantification of the extent of improvement is not an easy task since var-iations on the catalysts' specific areas and pore structures might involve modifications on a number of other surface catalytic features. This study establishes the impact of the catalyst textural properties on the CO2 methanation performance by investigating bimetallic Ni-Fe catalysts supported over carbon supports with different textural properties regarding surface area and pore structure. The comparable metal loading and dis-persions attained for all systems enabled establishing forthright relationships between the catalyst textural properties and CO2 methanation rate. Once the influence of the external mass diffusions on the catalysts' per-formance was experimentally discarded, the estimated Thiele modulus and internal effectiveness (phi and eta Eff) values showed that the catalyst performance was majorly governed by the surface reaction rate whilst the pore size affected in no significant manner within the examined range (Dpore = 10.2 to 5.8 nm). Therefore, the rapport between the catalyst performance and surface area was quantified for the CO2 methanation reaction over Ni-Fe catalysts: increasing the surface area from 572 to 802 m2/g permit obtaining ca. 10% higher CO2 conversions.

Automated summary

This study explores the impact of catalyst textural properties on CO2 methanation performance, finding that surface reaction rate is mainly affected by catalyst textural properties, while pore size has a limited impact. Increasing the surface area of Ni-Fe catalysts from 572 to 802 m2/g leads to approximately 10% higher CO2 conversions.