Runduo Zhang

Potential to use mesoporous carbon as catalyst support for hydrodesulfurization

Abstract A range of mesoporous carbons as potential supports to enhance ultra-deep hydrodesulphurization (HDS) of diesel fuel was synthesized using a sol-gel method. SBA-15 was used as template and sucrose and furfuryl alcohol were used as carbon sources. Various carbon incorporation approaches were used. From the results of nitrogen adsorption, transmission electron microscopy and X-ray diffraction, the synthesized carbon exhibited good replication of the SBA-15 structure. Loading of Co-Mo into the mesoporous carbons and catalysis dispersion were evaluated using various techniques including X-ray photoelectron spectroscopy and energy dispersive X-ray analysis. The intrinsic HDS activity was evaluated by NO chemisorption on the prepared catalysts, which showed that the catalyst supported on mesoporous carbon using sucrose as carbon precursor has a higher NO uptake than that supported on commercial activated carbon.

Optimization of Mixed Ag Catalysts for Catalytic Conversions of NO and C3H6

In order to adjust the redox properties of perovskite-based silver catalysts to satisfy the requirements for their application under overstoichiometric oxygen conditions (lean burn), three mixtures were prepared [Mixture (I): 10% La0.88Ag0.12FeO3 + 90% Al2O3; Mixture (II): 3% Ag/(10% La0.88Ag0.12FeO3 + 90% Al2O3); Mixture (III): 10% La0.88Ag0.12FeO3 + 90% (3%Ag/Al2O3)]. Mixture (I) with only a 10% La0.88Ag0.12FeO3 blend exhibited a NO reduction behavior similar to that of La0.88Ag0.12FeO3 alone at stoichiometric oxygen (1% O2). NO conversion of La0.88Ag0.12FeO3 under an excess of oxygen (10% O2) was however significantly improved by mixing with Al2O3 resulting in a value of ~ 30% at >400 °C in the case of Mixture (I). Ag impregnation facilitated the NO catalytic reduction, leading to a better deNOx performance for Mixture (II) and Mixture (III) than that of Mixture (I). It was also found that those silver atoms associated with Al2O3 are more effective for NO transformation. Therefore, the optimal mixed catalyst was Mixture (III), which shows satisfactory NO reduction and C3H6 oxidation at 500 °C under the whole range of O2 content from 1% to 10%.