Abatement of CH4 emitted by CNG vehicles using Pd-SBA-15 and Pd-KIT-6 catalysts

Abstract Compressed Natural Gas (CNG) engines are growing in interest in the car market due to their ability in the limitation of NO x and CO 2 emissions. Unburned methane is harder to oxidize than gasoline-derived unconverted HCs and its strong greenhouse effect induces the development of tailored after treatment technologies. In this work, SBA-15 and in particular KIT-6 have been used as supports for Pd catalysts for the abatement of methane emitted by CNG engines. The synthesized materials have been characterized through XRD, N 2 -adsorption/desorption, EDX, STEM, and TEM analysis techniques. The influence of different pore structure and size of the mesoporous supports as well as of different Pd loading (in the range 0.25–0.7 wt%) on the activity has been investigated. All mesoporous silica supported Pd catalysts showed almost complete conversion of methane, although catalysts with the lowest Pd loadings reached 90% of conversion over 650 °C, whereas the maximum Pd loadings allowed to decrease the temperature of complete conversion, with T 90 at 405 °C by employing the KIT-6 mesoporous silica support.

[1]  I. Rossetti,et al.  Perovskite catalysts for the catalytic flameless combustion of methane , 2000 .

[2]  F. Schüth,et al.  Ordered mesoporous materials , 1999 .

[3]  J. Mizuki,et al.  Redox behavior of palladium at start-up in the Perovskite-type LaFePdOx automotive catalysts showing a self-regenerative function , 2005 .

[4]  Xingyi Wang,et al.  Role of acidity of catalysts on methane combustion over Pd/ZSM-5 , 2007 .

[5]  S. Ihm,et al.  Characteristics of CoMo Catalysts Supported on Modified MCM-41 and MCM-48 Materials for Thiophene Hydrodesulfurization , 2006 .

[6]  M L Poulton.  Alternative Fuels for Road Vehicles , 1994 .

[7]  L. Kiwi-Minsker,et al.  Pd/SiO2 catalysts: synthesis of Pd nanoparticles with the controlled size in mesoporous silicas , 2003 .

[8]  N. Russo,et al.  New optimized mesoporous silica incorporated isolated Ti materials towards improved photocatalytic reduction of carbon dioxide to renewable fuels , 2015 .

[9]  Yi Zhang,et al.  Morphosynthesis route to large-pore SBA-15 microspheres , 2006 .

[10]  Patrick Da Costa,et al.  Catalytic combustion of methane over mesoporous silica supported palladium , 2011 .

[11]  G. Groppi,et al.  Catalytic Combustion for the Production of Energy , 1999 .

[12]  C. Dujardin,et al.  Surface reconstruction of supported Pd on LaCoO3 : consequences on the catalytic properties in the decomposition of N2O , 2008 .

[13]  G. Pantaleo,et al.  Pd (1 wt%)/LaMn0.4Fe0.6O3 Catalysts Supported Over Silica SBA-15: Effect of Perovskite Loading and Support Morphology on Methane Oxidation Activity and SO2 Tolerance , 2012, Topics in Catalysis.

[14]  A. Jiménez-lópez,et al.  Glucose dehydration to 5-hydroxymethylfurfural on zirconium containing mesoporous MCM-41 silica catalysts , 2014 .

[15]  S. Ihm,et al.  Synthesis of hydrothermally stable MCM-41 by the seed crystallization and its application as a catalyst support for hydrodesulfurization , 2007 .

[16]  K. Yi,et al.  Reactive adsorption of sulfur compounds in diesel on nickel supported on mesoporous silica , 2008 .

[17]  M. Islam,et al.  Oxygen Diffusion in LaMnO3and LaCoO3Perovskite-Type Oxides: A Molecular Dynamics Study , 1996 .

[18]  L. Pettersson,et al.  Exhaust Gas Catalysts for Heavy-Duty Applications: Influence of the Pd Particle Size and Particle Size Distribution on the Combustion of Natural Gas and Biogas , 2001 .

[19]  Debora Fino,et al.  Novel mesoporous silica supported ZnO adsorbents for the desulphurization of biogas at low temperatures , 2012 .

[20]  D. Fino,et al.  N2O decomposition by mesoporous silica supported Rh catalysts. , 2012, Journal of hazardous materials.

[21]  N. Yamazoe,et al.  Oxidation catalysis of perovskites --- relationships to bulk structure and composition (valency, defect, etc.) , 1990 .

[22]  Robert J. Farrauto,et al.  Palladium catalyst performance for methane emissions abatement from lean burn natural gas vehicles , 1997 .

[23]  M. Farias,et al.  Effect of redox treatments on activation and deactivation of gold nanospecies supported on mesoporous silica in CO oxidation , 2013 .

[24]  Yan Liu,et al.  Al-MCM-41 supported palladium catalyst for methane combustion: Effect of the preparation methodologies , 2009 .

[25]  J. Fierro,et al.  Properties and Applications of Perovskite-Type Oxides , 1992 .

[26]  R. Luque,et al.  Catalytic applications of mesoporous silica-based materials , 2012 .

[27]  Debora Fino,et al.  CNG engines exhaust gas treatment via Pd-Spinel-type-oxide catalysts , 2006 .

[28]  A. Bhaumik,et al.  3-D ordered mesoporous KIT-6 support for effective hydrodesulfurization catalysts , 2009 .

[29]  D. Fino,et al.  Development of modified KIT-6 and SBA-15-spherical supported Rh catalysts for N2O abatement: From powder to monolith supported catalysts , 2014 .

[30]  I. Rossetti,et al.  Catalytic flameless combustion of methane over perovskites prepared by flame–hydrolysis , 2001 .