Hi dr. Dutta,

first - It seems that there are peaks H2 ads/desorb. on Pt, or Pd. not on C. usually the peaks current not depended from OH concentration (~0.1 to ~1 M). 

Try to receeve the effect on bare Pt/Pt electrode with area

Thanks for your reply. But it is happening in our case that diluting the electrolyte solution i.e from 1 M to 0.25 M, a small hump has been found in the hydrogen adorp/desorption region.

 Hi Dr. Dutta,

If you received the hump on Pt/Pt (A,0.1 cm2) it will beinteresting

regards

boris f

In my case the catalyst is commercial Pd/C.

Regards,