A composition is provided that has heat resistance sufficient for use as a hydrocarbon adsorbent and desorbs hydrocarbons slowly with respect to an increase in temperature. The composition includes an alkali metal and a zeolite having a YFI structure. A content of the alkali metal is 1 to 40 mass % based on a total mass of the composition, and a content of the zeolite having a YFI structure is 99 to 60 mass % based on the total mass of the composition.

The invention relates to a noxious gas purificant and its preparation and purification method for removing nitrogen oxides from gas streams thereof. The preparing method is characterized in that: mixing, according to a predetermined ratio and a process, a salt of iron, manganese, cobalt, or copper, and a related derivative thereof, an alkali or alkaline substance and a related derivative thereof, water and a forming agent, so as to obtain a solid compound or mixture; drying and activating the solid compound or mixture to produce a solid product as the purificant; and introducing the purificant into a gas-solid reactor, and removing noxious gases in a gas stream by performing, in a preconfigured temperature and using the purificant, a gas-solid reaction on the harmful gases in the gas stream. The purificant can be recycled and reused.

Proposed is a method for manufacturing a catalyst for capture and conversion of carbon dioxide capable of removing carbon dioxide and converting carbon dioxide into other useful materials at the same time by capturing and converting carbon dioxide in flue gas generated during fossil fuel combustion into a carbon resource and a catalyst for capture and conversion of carbon dioxide manufactured by the method of the same. The catalyst for capture and conversion of carbon dioxide according to the present disclosure can reduce carbon dioxide by capturing carbon dioxide in flue gas generated during fossil fuel combustion. It is possible to convert the captured carbon dioxide into other useful materials by converting the collected carbon dioxide into sodium carbonate or sodium hydrogen carbonate as carbon resources.