The major function of having precious metals coated with carriers is that it can provide with larger touchable square measure . therefore , it can provide the largest surface square measure and held - up time . equilibrium tight intensity can provide gas with good mixable degree and even step - down in order not to cause slanting flow 将贵金属披覆于担体上,主要功能为提供较大的接触面积,因此可提供最大的表面积及滞留时间,均衡的紧密度可提供气体好的混合程度及均匀的压降,不致造成偏流。