Method for reducing pollution emissions from a diesel engine

Claim 1

A method for increasing the combustion efficiency of a diesel engine comprising a) preparing a diesel engine such that the injection timing thereof is set before top dead center at a level sufficient to obtain reductions in the nitrogen oxides emissions from the engine; and b) firing the diesel engine with a diesel fuel having admixed therein an additive which comprises a fuel soluble organometallic platinum group metal coordination composition selected from the group consisting of i) a composition of the general formula L.sup.1 PtR.sup.1 R.sup.2 wherein L 1 is either a single cyclic polyolefin or nitrogenous bidentate ligand or a pair of nitrogenous or acetylenic monodentate ligands; and R 1 and R 2 are each, independently, substituted or unsubstituted methyl, benzyl, aryl, cyclooc-tadiene or pentamethyl cyclopentadiene; ii) a composition of the general formula L.sup.2 M.sup.1 R.sup.3 wherein L 2 is either a single cyclic polyolefin or nitrogenous bidentate ligand or a pair of nitrogenous or acetylenic monodentate ligands; M 1 is rhodium or iridium; and R 3 is cyclooctadiene or pentamethyl cyclopentadiene; iii) a composition of the general formula L.sup.3 M.sup.2 (C.sub.r R.sup.4.sub.4) wherein L 3 is either a single cyclic polyolefin or nitrogenous bidentate ligand or a pair of nitrogenous monodentate ligands; M 2 is a platinum, palladium, rhodium or iridium; and R 4 is COOR 5 , wherein R 5 is hydrogen or alkyl having from 1 to 10 carbons; iv) a composition of the general formula L.sup.4 M.sup.3 (COOR.sup.6).sub.2 or a dimer thereof, wherein L 4 is a non-nitrogenous cyclic polyolefin ligand; M 3 is platinum or iridium; and R 6 is alkyl; v) a composition comprising the reaction product of L 5 RhX and R 7 MgX wherein L 5 is a non-nitrogenous cyclic polyolefin ligand; R 7 is methyl, benzyl, aryl, cyclooctadiene or pentamethyl cyclopentadiene; and X is a halide, wherein said platinum group metal compound is provided in an amount effective to supply from 0.01 to 1.0 parts per million of platinum group metal per part of fuel. vi) palladium acetylene complexes having the general formula ##STR4## wherein R 8 is aryl or alkyl; and R 9 is aryl; vii) metal allyl complexes having the general formula M.sup.r (C.sub.3 H.sub.5).sub.3 wherein M 4 is rhodium or iridium; viii) platinum (IV) compositions having the general formula R.sup.9.sub.3 PtR.sup.10 wherein R 9 is aryl, alkyl or mixtures thereof; and R 10 is hydroxyl, acetylacetonate, cyclopentadiene or pentamethyl cyclopentadiene; and ix) a composition of the general formula L.sup.6 M.sup.5 R.sup.13 wherein L 6 is substituted or unsubstituted butadiene or cyclohexadiene; M 5 is rhodium or iridium; and R 13 is cyclopentadiene or pentamethyl cyclopentadiene, wherein said composition A. is resistant to breakdown under ambient temperatures; B. contains no more than about 500 ppm phosphorus, arsenic, antimony or halides; and C. has a partition ratio sufficient to maintain preferential solubility in the fuel.

Claim 2

A method for increasing the combustion efficiency of a diesel engine comprising a) preparing a diesel engine such that the injection timing thereof is set before top dead center at a level sufficient to obtain reductions in the nitrogen oxides emissions from the engine; and b) firing the diesel engine with a diesel fuel having admixed therein an additive which comprises a fuel soluble organometallic platinum group metal coordination composition selected from the group consisting of i) a composition of the general formula L.sup.1 PtR.sup.1 R.sup.2 wherein L 1 is either a single cyclic polyolefin or nitrogenous bidentate ligand or a pair of nitrogenous or acetylenic monodentate ligands; and R 1 and R 2 are each, independently, substituted or unsubstituted methyl, benzyl, aryl, cyclooc-tadiene or pentamethyl cyclopentadiene; ii) a composition of the general formula L.sup.2 M.sup.1 R.sup.3 wherein L 2 is either a single cyclic polyolefin or nitrogenous bidentate ligand or a pair of nitrogenous or acetylenic monodentate ligands; M 1 is rhodium or iridium; and R 3 is cyclooctadiene or pentamethyl cyclopentadiene; iii) a composition of the general formula L.sup.3 M.sup.2 (C.sub.r R.sup.4.sub.4) wherein L 3 is either a single cyclic polyolefin or nitrogenous bidentate ligand or a pair of nitrogenous monodentate ligands; M 2 is a platinum, palladium, rhodium or iridium; and R 4 is COOR 5 , wherein R 5 is hydrogen or alkyl having from 1 to 10 carbons; iv) a composition of the general formula L.sup.4 M.sup.3 (COOR.sup.6).sub.2 or a dimer thereof, wherein L 4 is a non-nitrogenous cyclic polyolefin ligand; M 3 is platinum or iridium; and R 6 is alkyl; v) a composition comprising the reaction product of L 5 RhX and R 7 MgX wherein L 5 is a non-nitrogenous cyclic polyolefin ligand; R 7 is methyl, benzyl, aryl, cyclooctadiene or pentamethyl cyclopentadiene; and X is a halide, wherein said platinum group metal compound is provided in an amount effective to supply from 0.01 to 1.0 parts per million of platinum group metal per part of fuel. vi) palladium acetylene complexes having the general formula ##STR4## wherein R 8 is aryl or alkyl; and R 9 is aryl; vii) metal allyl complexes having the general formula M.sup.r (C.sub.3 H.sub.5).sub.3 wherein M 4 is rhodium or iridium; viii) platinum (IV) compositions having the general formula R.sup.9.sub.3 PtR.sup.10 wherein R 9 is aryl, alkyl or mixtures thereof; and R 10 is hydroxyl, acetylacetonate, cyclopentadiene or pentamethyl cyclopentadiene; and ix) a composition of the general formula L.sup.6 M.sup.5 R.sup.13 wherein L 6 is substituted or unsubstituted butadiene or cyclohexadiene; M 5 is rhodium or iridium; and R 13 is cyclopentadiene or pentamethyl cyclopentadiene, wherein said composition A. is resistant to breakdown under ambient temperatures; B. contains no more than about 500 ppm phosphorus, arsenic, antimony or halides; and C. has a partition ratio sufficient to maintain preferential solubility in the fuel.