Comprehensive characterization of engine deposits from fuel containing MMT.

Combustion chamber deposits from a 1996 GM3800 engine operating on a base fuel or the base fuel containing the organometallic antiknock additive methylcyclopentadienyl manganese tricarbonyl were examined. Scanning Electron Microscopy and Energy Dispersive X-ray spectroscopic analysis were performed to identify the morphology and the bulk chemical composition. Glow-Discharge Mass Spectrometry and X-ray Diffraction analyses were also used to characterize the bulk chemical composition and crystalline structure of the deposits. In addition, X-ray photoemission and X-ray photoabsorption spectra for the deposits were compared to a series of Mn compounds to model and aid quantification of the constituents. Results reveal a mixture of Ca-sulfate, Mn-phosphate and Mn-oxide in the bulk of the deposits and a mixture of Mn-sulfate, Mn-phosphate and Mn-oxide on the surface of the deposits.

[1]  L. B. Ebert,et al.  X-RAY DIFFRACTION OF N-PARAFFINS AND STACKED AROMATIC MOLECULES: INSIGHTS INTO THE STRUCTURE OF PETROLEUM ASPHALTENES , 1984 .

[2]  D. Hercules,et al.  Surface spectroscopic characterization of Cu/Al2O3 catalysts , 1985 .

[3]  C. Nordling,et al.  Molecular Spectroscopy by Means of ESCA II. Sulfur compounds. Correlation of electron binding energy with structure , 1970 .

[4]  W. Stickle,et al.  Handbook of X-Ray Photoelectron Spectroscopy , 1992 .

[5]  M. Chan,et al.  Ligand Field Strengths and Oxidation States from Manganese L-Edge Spectroscopy , 1991 .

[6]  T. Matsushita,et al.  Evaluation of Mn3s X-ray photoelectron spectroscopy for characterization of manganese complexes , 1995 .

[7]  T. Yen,et al.  Investigation of the Structure of Petroleum Asphaltenes by X-Ray Diffraction , 1961 .

[8]  I. Sutherland,et al.  An XPS study of ion-induced compositional changes with group II and group IV compounds , 1983 .

[9]  H. S. Homan,et al.  Fuel, Lubricant and Additive Effects on Combustion Chamber Deposits , 1998 .

[10]  T. Stemmler,et al.  Manganese L-Edge X-ray Absorption Spectroscopy of Manganese Catalase from Lactobacillus plantarum and Mixed Valence Manganese Complexes , 1996 .

[11]  J. Stöhr.  Principles, Techniques, and Instrumentation of NEXAFS , 1992 .

[12]  L. Terminello,et al.  Analysis of manganese particulates from automotive decomposition of methylcyclopentadienyl manganese tricarbonyl , 1999 .

[13]  A. Nelson,et al.  Core-level satellites and outer core-level multiplet splitting in Mn model compounds , 1999 .

[14]  S. Cheng.  The Effects of Engine Oils on Intake Valve Deposits and Combustion Chamber Deposits , 1993 .

[15]  John R. Van Wazer,et al.  Inner-orbital photoelectron spectroscopy of the alkali metal halides, perchlorates, phosphates, and pyrophosphates , 1973 .

[16]  A. Aoki.  X-Ray Photoelectron Spectroscopic Studies on ZnS: MnF2 Phosphors , 1976 .

[17]  Joseph W. Roos,et al.  A Systems Approach to Improved Exhaust Catalyst Durability: The Role of the MMT Fuel Additive , 2000 .

[18]  J. D. Bailie,et al.  AN EVALUATION OF MANGANESE AS AN ANTIKNOCK IN UNLEADED GASOLINE , 1975 .

[19]  Thomas A. Carlson,et al.  Use of X‐Ray Photoelectron Spectroscopy to Study Bonding in Cr, Mn, Fe, and Co Compounds , 1972 .

[20]  Ryu,et al.  Charge-transfer satellites in the 2p core-level photoelectron spectra of heavy-transition-metal dihalides. , 1988, Physical review. B, Condensed matter.