Effect of La2O3 as a Promoter on the Pt,Pd,Ni/MgO Catalyst in Dry Reforming of Methane Reaction

Ali M A Al-Najar,Ali A A Al-Riyahee,Faris A J Al-Doghachi,Yun Hin Taufiq-Yap

doi:10.3390/catal10070750

Abstract

Pt,Pd,Ni/MgO, Pt,Pd,Ni/Mg0.97La3+0.03O, Pt,Pd,Ni/Mg0.93La3+0.07O, and Pt,Pd,Ni/Mg0.85La3+0.15O (1% of each of the Ni, Pd, and Pt) catalysts were prepared by a surfactant-assisted co-precipitation method. Samples were characterized by the XRD, XPS, XRF, FT-IR, H2-TPR, TEM, the Brunauer–Emmett–Teller (BET) method, and TGA and were tested for the dry reforming of methane (DRM). TEM and thermal gravimetric analysis (TGA) methods were used to analyze the carbon deposition on spent catalysts after 200 h at 900 °C. At a temperature of 900 °C and a 1:1 CH4:CO2 ratio, the tri-metallic Pt,Pd,Ni/Mg0.85La3+0.15O catalyst with a lanthanum promoter showed a higher conversion of CH4 (85.01%) and CO2 (98.97%) compared to the Ni,Pd,Pt/MgO catalysts in the whole temperature range. The selectivity of H2/CO decreased in the following order: Pt,Pd,Ni/Mg0.85La3+0.15O > Pt,Pd,Ni/Mg0.93La3+0.07O > Pt,Pd,Ni/Mg0.97La3+0.03O > Ni,Pd,Pt/MgO. The results indicated that among the catalysts, the Pt,Pd,Ni/Mg0.85La23+0.15O catalyst exhibited the highest activity, making it the most suitable for the dry reforming of methane reaction.

Highlights

The dry reforming of methane (DRM) (Equation (1)) is a promising reaction for the simultaneous conversion of two major greenhouse gases (CO2 /CH4 ) to syngas with an H2 /CO ratio of 1 and is suitable for the synthesis of oxygenated hydrocarbons and synthetic fuels [1]
The results indicated that among the catalysts, the Pt,Pd,Ni/Mg0.85 La2 3+ 0.15 O catalyst exhibited the highest activity, making it the most suitable for the dry reforming of methane reaction
No diffraction peaks were observed for Pt, Pd, and Ni due to their low concentration

Summary

Introduction

The dry reforming of methane (DRM) (Equation (1)) is a promising reaction for the simultaneous conversion of two major greenhouse gases (CO2 /CH4 ) to syngas with an H2 /CO ratio of 1 and is suitable for the synthesis of oxygenated hydrocarbons and synthetic fuels [1]. The main drawbacks of DRM are as follows: (1) the catalyst sintering at high temperature; (2) the occurrence of the reverse water–gas shift reaction (RWGS) (Equation (2)). Catalysts containing noble metals, such as Pt, Ru, and Rh, show high activity and selectivity for the DRM reaction as well as good stability towards coke deposition; their high cost and low availability make them not economically competitive in comparison to other transition metal-based materials [5,6,7]. Among non-precious transition metals, cobalt and nickel supported on various oxide systems (MgO-ZrO2 , Al2 O3 , MgAl2 O4 , CeO2 , CeO2 -ZrO2 ) showed promising performances

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