摘要:
A catalyst for purifying exhaust gas comprising crystalline iridium silicate having a Si/Ir atomic ratio of 50 to 800 and a Si/Al atomic ratio of not less than 15. The catalyst exhibits excellent activity and selectivity when used for purification of, and specifically for eliminating NOx from, an exhaust gas which contains reducing components including hydrocarbons, oxygen in excess of the stoichiometric quantity necessary for completely oxidizing all of the reducing components, and nitrogen oxides. The catalyst is highly durable to hydrothermal aging.
摘要:
A catalyst for selective oxidation of carbon monoxide present in a hydrogen-containing gas is provided in which the catalyst comprises ruthenium supported on an alumina hydrate. This catalyst has a high selective oxidation activity to carbon monoxide. A carbon monoxide elimination method using this catalyst is also provided. In this method, to a gas containing at least hydrogen and carbon monoxide and being richer in the hydrogen than the carbon monoxide on the basis of volume, oxygen is added in an amount necessary for oxidizing at least part of carbon monoxide present in that gas, and thereafter the gas to which the oxygen has been added is brought into contact with the catalyst described above. Also provided is a solid polymer electrolyte fuel cell system that utilizes this method.
摘要:
A catalyst for selective oxidation of carbon monoxide present in a hydrogen-containing gas is provided in which the catalyst comprises ruthenium supported on an alumina hydrate. This catalyst has a high selective oxidation activity to carbon monoxide. A carbon monoxide elimination method using this catalyst is also provided. In this method, to a gas containing at least hydrogen and carbon monoxide and being richer in the hydrogen than the carbon monoxide on the basis of volume, oxygen is added in an amount necessary for oxidizing at least part of carbon monoxide present in that gas, and thereafter the gas to which the oxygen has been added is brought into contact with the catalyst described above. Also provided is a solid polymer electrolyte fuel cell system that utilizes this method.
摘要:
A catalyst for selectively oxidizing carbon monoxide in a hydrogen-containing gas comprises an alumina hydrate carrier and at least platinum supported thereon. With an aluminum hydrate as a carrier, the catalyst is resistant to deactivation which would be caused by an oxygen-containing hydrocarbon in a hydrogen-rich gas. The method for selectively removing carbon monoxide comprises the steps of adding oxygen to a hydrogen-rich gas containing carbon monoxide, in an amount necessary to oxidize at least part of carbon monoxide, and bringing the resulting mixture into contact with the catalyst for selectively oxidizing carbon monoxide. The solid polymer electrolyte-type fuel cell system utilizes the above method for selectively removing carbon monoxide.
摘要:
The present invention provides a catalyst and method for purifying exhaust gases, having superior performance of NOx purification to exhaust gases containing oxygen and nitrogen oxides, particularly superior performance of NOx elimination to exhaust gases from lean-bum engines with excess oxygen, and a wider effective temperature range of NOx elimination, and also superior heat resistance at high temperature, said catalyst for purifying exhaust gases comprises, as indispensable contents, iridium and alkaline metal loaded on a carrier which is at least one selected from metal carbide and metal nitride, or these and at least one element selected from the group consisting of alkaline earth metal elements and rare earth metal elements, and said method using these catalyst.