It looks like unusual. I think an Error was occurred during BJH test.

It appears your pore dist. curve is missing the initial points. Check with your data (if you have the original from the software) before rerunning the test. Seems the pore size is somewhere around 2-3 nm so you do not need to show beyond 10 though the hump might refer to some macroporosity but still strange.

You have a typical Type IV isotherm. Asumming that you are using the BJH method on the Desorption curve then delete the lowest three points but start the calculations from points closer to a relative pressure of 1. Your pores should be about 8.5 nm width. Your problem is that your first point on the Desorption cycle appears to be at a relative pressure of about 0.85 and you have ignored the wider mesopores.

Thanks for answers.

Dear Professor Yates,

That figure was based on BJH Adsorption curve.

The attached image is based on Desorption curve.