艾西阀门怎么样:翻译—语言是最厚的墙1

3.3. Effect of additives on the water gas shift reaction
The water gas shift reaction has been investigated mainly from the standpoint of methanol synthesis and ammonia synthesis processes [25]. Both metals and metal oxides readily catalyze the reaction. Research conducted on the WGS reaction has been very extensive. Rhodes et al. [26] reviewed literature on the WGS reaction and suggested that the catalyst performance can be dramat- ically affected by very small changes in the catalyst composition.

Mellor [27] studied the water gas shift reaction over Raney® copper catalysts and revealed that about 70% of the experimental results can be explained in terms of a linear relation between activity and copper surface area. Studies in this laboratory [28] also showed that the addition of small amounts of Cr2O3 in skeletal Cu significantly enhanced the specific surface area by changing the pore structure and size, thereby improving the activity for the WGS reaction. In this study, the effect of different additives on the WGS
activity is illustrated in Fig. 4. It is noted that the addition of 0.1% Cr2O3 on the surface increased the rate from 6.9×10.2 to 19 × 10.2 mol/h g-cat. However, the activity decreased with further increases of Cr2O3 loading, presumably due to an overload of Cr additive on the surface, which decreased the apparent copper surface area (Fig. 1).