The invention relates to a preparation method of a kind of modified
silicon gel absorbing agent used for protecting on-vehicle fuel batteries, which belongs to the
branch of the non-metallic inorganic
material technology and is applied to the field of gas absorption and separation. The preparation method uses 3-aminopropyl
triethoxysilane as amino modifying agents, uses tetraethoxy
silane as
silicon gel precursors, and prepares and obtains modified
silicon gel with uniformly decorated amino groups in a
porous silicon gel framework through adding a certain number of amino modifying agents in the
gel forming stage. The absorbing agent can be used for removing a trace amount of
sulfur dioxide in the air, so cathodic catalysts of on-vehicle
proton exchange membrane fuel batteries are protected from the poisoning effect of the
sulfur dioxide. Compared with the prior art, the invention has the following advantages that: (1) the obtained absorbing agent has better capability for absorbing the trace amount of
sulfur dioxide than
active carbon fiber, the effect is shown through longer penetrating time and larger saturation adsorption capacity, in addition, the absorbing agent still has good absorbing capability when the
humidity is lower; and (2) the obtained absorbing agent has simple and convenient preparation method, the operation is easy, the condition is mild, and the effects of energy saving and environment protection can be obtained.