How can develop and under  develop countries benefit from carbon credit? 

Dear Vidisha,

The catalyst 100 mesh size is better

Structural Properties of the Ni/Al2O3 catalysts

Al2O3 Pore Diameter 6.0457 nm

Ni/Al2O3 pore diameter 5.7681 nm

Regards,

Prem Baboo

Vidisha, it is difficult to tell for certain which size is better without experimental data. Depends on a catalyst. In some cases it is smallest size, in some cases certain size gives best results. Just tell which catalyst you use. 

If you are talking about producing hydrogen by catalytic decomposition of methane then catalyst reduced to particular mesh size is more helpful. It depends upon the type of catalyst one is using. For example if Fe-Ni or Fe-Mo supported over silica is used as a catalyst then 100 mesh size is preferred.