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Catalysts 2014, 4(2), 196-214; doi:10.3390/catal4020196
Review

Deactivation Pattern of a “Model” Ni/MgO Catalyst in the Pre-Reforming of n-Hexane

1
 and 1,2,*
Received: 14 August 2013; in revised form: 20 January 2014 / Accepted: 5 June 2014 / Published: 19 June 2014
(This article belongs to the Special Issue Advances in Catalyst Deactivation)
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Abstract: The deactivation pattern of a “model” Ni/MgO catalyst in the pre-reforming of n-hexane with steam (T, 450 °C; P, 5–15 bar) is reviewed. The influence of the steam-to-carbon ratio (S/C, 1.5–3.5) on the rate of catalyst fouling by coking is ascertained. Catalyst fouling leads to an exponential decay in activity, denoting 1st-order dependence of the coking process on active sites availability. Hydrogen hinders the coking process, though slight activity decay is due to sintering of the active Ni phase. Deactivation by thiophene causes a sharp, almost linear, drop to nearly zero activity within only 6 h; this deactivation is likely due to dissociative adsorption of thiophene with subsequent strong, irreversible chemical adsorption of S-atoms on active Ni sites, i.e., irreversible poisoning. Modeling of activity decay curves (α, at/a0) by proper kinetic equations allows assessing the effects of temperature, pressure, S/C, H2 and thiophene feed on the deactivation pattern of the model Ni/MgO catalyst by coking, sintering, and poisoning phenomena.
Keywords: pre-reforming; activity decay; poisoning; sintering pre-reforming; activity decay; poisoning; sintering
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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MDPI and ACS Style

Trunfio, G.; Arena, F. Deactivation Pattern of a “Model” Ni/MgO Catalyst in the Pre-Reforming of n-Hexane. Catalysts 2014, 4, 196-214.

AMA Style

Trunfio G, Arena F. Deactivation Pattern of a “Model” Ni/MgO Catalyst in the Pre-Reforming of n-Hexane. Catalysts. 2014; 4(2):196-214.

Chicago/Turabian Style

Trunfio, Giuseppe; Arena, Francesco. 2014. "Deactivation Pattern of a “Model” Ni/MgO Catalyst in the Pre-Reforming of n-Hexane." Catalysts 4, no. 2: 196-214.


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