Deactivation studies of noble metal catalysts for lean methane combustion

• Author / Creator

  Istratescu, Georgeta M.

• Green House Gases (GHG) contribution to global warming has led to extensive research into reduction of emission of the GHG. Transportation, as a main contributor to GHG, faces a major challenge in researching and developing of new technologies with the aim of reducing the carbon foot print. The use of alternative fuels with lower harmful emissions became obvious as a result of emission control regulations and climate change. Natural gas engines gained popularity due to their ability to burn the fuel almost completely, which recommends them as an environmentally friendly alternative to fossil fuels engines. However, the incomplete combustion of methane in natural gas engines will release methane and carbon monoxide into the atmosphere. The fugitive methane emission problem can be tackled by the development of performant catalytic converters.
  This project reports on catalytic activity and stability of three sets of catalyst. The first set, palladium only catalysts provided by 15, 80 and 150 g/ft3 loading, were designed for methane combustion but not necessarily for lean burn engines. The second set studied were 2 catalysts: Pt and Pt-Pd (4:1) catalyst, with a loading of 95 g/ft3. Their mainly intend was the use as diesel oxidation catalysts. The third set of catalytic converters was designed for use for lean burn gas engines. The catalysts studied were Pt-Pd (1:5) with a loading of 150 g/ft3, Pd 122 (122 g/ft3), Pd Rh (117.15:2.85) (loading 120 g/ft3) and PtPdRh (19:73:2.85) with a loading of 94.85 g/ft3. The influence of different pretreatments on the catalyst activity (i.e. de-greening temperature, reduction process) were studied through ignition-extinction experiments. The stability of the catalyst was investigated through thermal ageing experiments. The effect of water on the catalytic activity was investigated through hydro-thermal ageing experiments.

• Subjects / Keywords

  • Hydro-thermal ageing
  • Reduction effect
  • Thermal ageing
  • Particle size effect
  • Sintering effect
  • Atmosphere effect
  • Noble metal catalysts for methane combustion
  • Re-dispersion of the catalyst

• Graduation date

  Spring 2014

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/R3KP7V05F

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.