(758f) Ni-MgO Stable and Active Catalysts for the Dry Reforming of Methane Prepared By Paper Assisted Combustion Synthesis

Ni-MgO Stable and Active Catalysts for the Dry
Reforming of Methane Prepared by Paper Assisted Combustion Synthesis

V. Danghyan,
A. Mukasyan and E. E. Wolf

Department
of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame,
IN

We
have recently investigated the pathway of carbon formation on Ni/SiO₂
catalysts and prepared a highly stable and active catalyst using a novel method
of impregnation by pressure dilution [1]. Following our findings on the carbon
deposition pathway, we present new results on Ni-MgO catalyst using a new
preparation method referred as paper assisted impregnated solution combustion
synthesis (PA-ISCS) that have resulted in a very active and stable catalysts
for the DRM reaction. For comparison catalysts were also prepared by solution
combustion synthesis (SCS) without paper-templating [2].

Fig.1 shows that methane conversion at 600^oC
is 50 and 60% respectively for the 20%Ni-MgO and 10%Ni-MgO catalysts prepared
by PA-ISCS and its remaining constant during over 20 h of time on stream (TOS).
On the other hand, the 10%Ni-MgO catalyst prepared without paper assistance
reaches only 35% methane conversion and starts decreasing at about 22h TOS.
Carbon content is ~ 4% for the PA-ISCS 10%Ni-MgO catalyst and 26% for the SCS
catalyst without paper assistance. The activation energies decreased from ~94,
88, 66 kJ/mol with nickel content from 5, 10 and 20%.

The structure of the catalysts was imaged by SEM (fig
2), which shows that the catalyst (2a) prepared by the PA-ISCS method exhibits
a structure that is similar to the structure of the filter paper fibers (2b).
This leads to higher surface area and smaller crystallite size. As previously
reported formation of carbon during the DRM depends on Ni crystallite size.

Additional
results indicate that the PA-ISCS synthesis method results in an active and
stable catalyst due to the interaction of the filter paper acting as template
for the mixture of Ni and Mg nitrates fueled with glycine during SCS.

References:

(1) Danghyan, V.; Calderon Novoa, S.; Mukasyan, A.; Wolf, E.E.
Appl. Catal. B. 2018; 234, 178-186.

(2) Cross, A.; Kumar A.; Wolf E.E.;
Mukasyan A.S. Ind. Eng. Chem. Res. 2012; 37, 51.