Hydrocarbon oxidation and three-way catalytic activity on a single step directly coated cordierite monolith : High catalytic activity of Ce0.98Pd0.02O2-δ

• Published in: Applied catalysis. A, General General, 2008-03, Vol.337 (2), p.130-137
• Main Authors: SHARMA, Sudhanshu, HEGDE, M. S, RATINDRA NATH DAS, PANDEY, Manish
• Format: Article
• Language: English
• Subjects: Catalysis; Chemistry; Exact sciences and technology; General and physical chemistry; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry
• ISSN: 0926-860X; 1873-3875
• DOI: 10.1016/j.apcata.2007.10.028

Catalytic activity of cordierite honeycomb by a completely new coating method for the oxidation of major hydrocarbons in exhaust gas is reported here. The new coating process consists of (a) dipping and growing gamma-Al2O3 on cordierite by combustion of monolith dipped in the aqueous solution of Al(NO3)3 and oxalyldihydrazide (ODH) (or glycine) at 600 deg C and active catalyst phase Ce0.98Pd0.02O2-delta on gamma-Al2O3-coated cordierite again by combustion of monolith dipped in the aqueous solution of ceric ammonium nitrate, ODH and 1.2X10-3M PdCl2 solution at 500 deg C. Weight of active catalyst can be varied from 0.02wt% to 2wt% which is sufficient but can be loaded even up to 12wt% by repeating dip dry combustion. Adhesion of catalyst to cordierite surface is via oxide growth, which is very strong. 'HC' oxidation over the monolith catalyst is carried out with a mixture having the composition, 470ppm of both propene and propane and 870ppm of both ethylene and acetylene with the varying amount of O2. Three-way catalytic test is done by putting hydrocarbon mixture along with CO (10000ppm), NO (2000ppm) and O2 (15000ppm). Below 350 deg C full conversion is achieved. In this method, handling of nano-material powder is avoided.