Ni Catalysts Supported on Modified Alumina for Diesel Steam Reforming

Abstract

Nickel catalysts are the most popular for steam reforming, however, they have a number of drawbacks, such as high propensity toward coke formation and intolerance to sulfur. In an effort to improve their behavior, a series of Ni-catalysts supported on pure and La-, Ba-, (La+Ba)-and Ce-doped γ-alumina has been prepared. The doped supports and the catalysts have been extensively characterized. The catalysts performance was evaluated for steam reforming of n-hexadecane pure or doped with dibenzothiophene as surrogate for sulphur-free or commercial diesel, respectively. The undoped catalyst lost its activity after 1.5 h on stream. Doping of the support with La improved the initial catalyst activity. However, this catalyst was completely deactivated after 2 h on stream. Doping with Ba or La+Ba improved the stability of the catalysts. This improvement is attributed to the increase of the dispersion of the nickel phase, the decrease of the support acidity and the increase of Ni-phase reducibility. The best catalyst of the series doped with La+Ba proved to be sulphur tolerant and stable for more than 160 h on stream. Doping of the support with Ce also improved the catalytic performance of the corresponding catalyst, but more work is needed to explain this behavior.

Hydrogen‐rich syngas production from chemical looping steam reforming of bio‐oil model compound: Effect of bimetal on LaNi 0.8 M 0.2 O 3 (M = Fe, Co, Cu, and Mn)

“…The LNCo is easily formatted from graphitic coke which conversion needs to consume high temperature. Coke formation is the main reason for the catalyst deactivation because it can deposit the surface of catalysts as well as the metal active sites . On the other hand, the doping of Fe to Ni‐based perovskite type oxide enhanced the catalytic activity and stability due to synergistic interactions of Ni and Fe to form bimetallic Ni‐Fe particles …”

Numerical Simulation and Experimental Study on Commercial Diesel Reforming Over an Advanced Pt/Rh Three-Way Catalyst

“…Nevertheless, one of the biggest difficulties, particularly for mobile generation set, is the lack of existing infrastructure of hydrogen production nowadays [3]. In view of the foregoing case, some studies have sought to adopt hydrocarbon fuel reforming to supply hydrogen into fuel cell generation sets efficiently [4][5][6][7][8][9][10][11]. Compared to the traditional internal combustion engine generation sets, a diesel fuel cell auxiliary power unit (APU) possess the merits of higher energy utilization efficiency and lower harmful tailpipe emissions [6].…”

Surface Chemistry and Catalysis

“…The impact of structural promoters (La, Ba, Ce) on the Diesel Steam Reforming (DSR) of Ni/Al 2 O 3 catalysts was explored in detail by Tribalis A. et al [9]. Incorporation of dopants into the Al 2 O 3 carrier was found to be always beneficial, but to a different extent, depending on the nature of the promoter.…”

“…It consists of 14 high-quality papers, involving: a comprehensive review article on the surface analysis techniques that can be employed to elucidate the phenomenon of electrochemical promotion in catalysis [3]; two theoretical studies (Density Functional Theory, DFT) on H 2 O dissociation and its implications in catalysis [4,5]; two mechanistic studies by means of temperature-programmed desorption/surface reaction (TPD/TPSR) and/or operando spectroscopy on N 2 O formation over NO x storage-reduction (NSR) catalysts [6] and on methanol reforming over cobalt catalysts [7]; two articles on H 2 production by the steam reforming of ethanol [8] or diesel [9] over transition metal-based catalysts; two articles on the production of commercial fuels by Fisher-Tropsch synthesis [10,11]; two articles on Au-catalyzed CO oxidation [12] and preferential CO oxidation [13]; and three experimental investigations regarding the structure-activity correlation of NO oxidation to NO 2 over Mn-Co binary oxides [14], cyclohexene oxidation on TiZrCo mixed oxides [15] and alkene epoxidation on silica nanoparticles [16].…”