Patent ID: 6242263
Filing Date: 2001-06-05
Classification: F01N,F02B,G01N,Y02T,Y10T

Abstract:
A system for measuring the hydrocarbon concentration of a gas sample, comprising:a sensor catalyst having an oxidation catalyst capable of selectively oxidizing the combination of CO+H.sub.2 +alkene hydrocarbons species in the gas sample, the sensor catalyst comprising an oxidation catalyst having a high surface area catalyst-support material and a precious metal layer comprising an amount of highly dispersed rhodium cluster deposits on the surface of a high surface area catalyst-support material, the rhodium cluster deposits comprising a single rhodium atom or a cluster of at least two rhodium atoms, the deposits having a diameter of less than about 5 nm and covering no greater than about 10% of the surface area of the catalyst-support material;a catalytic differential calorimetric sensor, capable of producing a output signal representative of the exothermic effect of the remaining aromatic and alkane hydrocarbons species in the gas sample; and,a heater for maintaining each of the sensor catalyst and the catalytic calorimetric sensor at a temperature sufficient to effect substantially complete oxidation of the CO+H.sub.2 +alkene hydrocarbon and aromatic and alkane hydrocarbon species, respectively;a means for analyzing the output signal representative of the concentration of unburned aromatic and alkane hydrocarbons in the exhaust gas to determine concentration of the total non-methane hydrocarbon species.