Methane catalytic oxidation catalyst for natural gas vehicle and preparation method of methane catalytic oxidation catalyst

Abstract

The invention relates to a methane catalytic oxidation catalyst for natural gas vehicle exhaust aftertreatment and a preparation method of the methane catalytic oxidation catalyst. The methane catalytic oxidation catalyst is a stannum-zirconium composite oxide solid solution catalyst, wherein the stannum / zirconium atomic ratio is at least 1.1, the general equation is Sn(1-x)ZrxM0.10O2, M is at least one of rare earth and transition metal, and x is a coefficient; the methane catalytic oxidation catalyst is prepared from the following components in percentage by weight: 50-70% of a stannic oxide (SnO2) precursor, 15-40% of a zirconium dioxide (ZrO2) precursor and the balance being a stabilizer oxide precursor. The preparation method sequentially comprises the following steps: (1) preparing mixed salt; (2) adding a precipitant-urea; (3) carrying out homogeneous precipitation reaction; and (4) roasting to obtain a finished product. The methane catalytic oxidation catalyst has the high active component content and can completely oxidize methane at about 500 DEG C, and the catalytic oxidation ability of a stannum-zirconium composite oxide solid solution on the methane, propane and carbon monoxide can be remarkably improved; and besides, the preparation method is simple, can be operated easily and is low in cost.

Description

technical field [0001] The invention relates to a catalyst, in particular to a methane catalytic oxidation catalyst for aftertreatment of exhaust gas from a natural gas vehicle and a preparation method thereof. Background technique [0002] As a clean energy, natural gas is taking an increasing proportion in the energy structure. However, the combustion temperature of its main component methane is very high, so the combustion efficiency is low, and a small amount of nitrogen oxides NO will be produced during the combustion process. X and other incomplete combustion products, resulting in environmental pollution. The oxygen-enriched combustion of methane in the presence of a catalyst is more in line with environmental protection requirements. [0003] The catalysts for the catalytic oxidation of methane for vehicles mainly include platinum Pt, palladium Pd, rhodium Rh and other supported noble metal catalysts, perovskite composite metal oxide catalysts and supported transit...

AI Technical Summary

Problems solved by technology

Platinum Pt, palladium Pd, rhodium Rh and other supported noble metal catalysts have good low-temperature catalytic activity for methane combustion, but these catalysts have problems such as high price, poor thermal stability and easy sintering, which limit their application in natural gas vehicles. The application of exhaust gas post-treatment, and perovskite composite metal oxide catalysts and supported transition metal oxide catalysts are also difficult to be used industrially due to factors such as small specific surface area, poor mechanical strength and low activity. Perovskite composite metal oxide catalysts In the strong exothermic reaction of oxide catalysts, there are still problems such as easy sintering at high temperature and easy loss of B-site short-period elements.