Evaluation of Pt-Ni/Al2O3.MgO catalysts for methane dry reforming

CAMILA A. PINTO; ADRIANA D. BALLARINI; SILVIA C.P. MAINA; ANDRÉ ROSA MARTINS; MARIA DO CARMO RANGEL; LUCIENE SANTOS CARVALHO

Lyon

Congreso; 11th European Congress on Catalysis ? EuropaCat-XI, Lyon, France; 2013

The production of both hydrogen gas and synthesis gas - a mixture of hydrogen and carbon monoxide may be performed by means of several technologies which involve the conversion of hydrocarbons such as steam reforming, dry reforming, partial oxidation or a combination of them such as autothermal reforming or mixed reforming with carbon dioxide and water [1]. Among them, the first two ones are the most employed. Dry reforming reaction is highly endothermic which provides a way to harness and recycle two greenhouse gases, methane and carbon dioxide, which are converted into important inputs and provide a pathway for the production of synthesis gas rich in carbon monoxide [2-4]. The synthesis gas with H2/CO ratio = 1 is useful for hydrocarbons and oxygenate synthesis. The main reaction in dry reforming is shown in Equation 1: ( ) (1) Catalysts used in this process typically contain nickel as the active phase, which exhibits good activity/cost rela-tionship, and can be supported on materials with thermal and mechanical resistance suitable to the operating condi-tions, such as alumina. However, the nickel/alumina catalyst deactivates quickly due to sintering and/or to pores blocking with a large amount of coke formed [5]. The literature [6-8] indicates the use of noble metals as catalysts for methane reforming due to its good perfor-mance and low carbon deposition. However, its low availability and high cost limits its large scale application. The addition of low concentration of noble metals such as Pt, Pd, Ru or Rh could modify the structural characteristics of nickel catalysts leading to bimetallic systems with good catalytic properties and less susceptible to coking at lower cost. Moreover, the support also has great influence on the performance of catalysts used in hydrocarbon reforming processes. Supports based on magnesium aluminate spinels which have low acidity and good stability at high tem-peratures employed in the reactions are of great interest for this application. The aim of this work is to study the behavior of platinum-nickel catalysts supported on aluminium and magne-sium oxide toward catalysts with high conversion of methane and carbon dioxide and high selectivity to hydrogen and synthesis gas for methane dry reforming process.