PRESENT POSITION AND OUTLOOK FOR THE CATALYTIC CLEANING OF GAS EMISSIONS - REVIEW

The review gives an analysis of the present position of catalyst resea rch aimed at solving ecological problems (ecological catalysis) in the cleaning of motor vehicle gas emissions. The analysis is based on dat a from the scientific and technical literature of the last five years. Information is given on existing and planned standards for the regula tion of emissions in the most developed countries of the world. Attent ion is concentrated chiefly on the removal of exhaust gases CO, NOx an d H2S in the presence of hydrocarbons. In accordance with modern trend s, processes of NOx removal are examined in most detail, including dat a from studying the mechanism and kinetics of catalytic breakdown, and also the selective catalytic reduction of NO by ammonia. Chemical sch emes of the mechanism of corresponding processes in the presence of me tal oxide and Cu-substituted zeolite catalysts are discussed. These ar e interpreted on the basis of data obtained by IR spectroscopy of surf ace intermediates.