Gasoline additives for catalytic control of emissions from combustion

Abstract

Catalytic metal additives that directly dissolve in gasoline in concentrations providing efficient and economical three-way catalysis of exhaust gases from internal combustion engines. The additives are compounds of noble (e.g., Pt, Pd, Au and Rh) or non-noble (e.g., Re) metals. The preferred compounds have polar metal ligand bonds, preferably with inorganic ligands such as halogens, oxygen, etc., and/or salts with highly ionic (polarizable) cations such as of alkali metals. The preferred additive is a combination of X.sub.2 PtCl.sub.6, RhCl.sub.3 and XReO.sub.4, where X=K, Rh or Cs. A combination of these finely ground materials is fabricated into a briquette or filter which is deposited in the gas tank or placed in a gas line. The catalytic metals are carried by the exhaust gases through the exhaust system where they are deposited on surfaces of the system to convert toxic emissions. In this way, the invention allows for the delivery of efficient gasoline additives without the use of solvents or extraneous agents.