| abstract |
Vehicular emissions are reduced/purified via combustion of the hydrocarbon fuel therefor, e.g., diesel fuel, in the presence of a cerium compound, preferably a cerium (IV) compound, to produce soots having depressed ignition temperatures that contain effective purifying amounts of aggregates of ceric oxide crystallites, the largest particle size dimension of which ranging from 50 ANGSTROM (5 nanometers) to 10,000 ANGSTROM (1,000 nanometers) and the crystallite sizes of which, measured by Debye-Scherrer technique, ranging from 50 ANGSTROM (5 nanometers) to 250 ANGSTROM (25 nanometers). |