adsorbent vs adsorptive

adsorbent is a noun but adsorptive is not a noun.

Word	Noun	Adjective	Verb	Adverb
adsorbent	Yes	Yes	No	No
adsorptive	No	Yes	No	No

As adjectives, adsorbent and adsorptive are synonyms defined as:

adsorbent and adsorptive: having capacity or tendency to adsorb or cause to accumulate on a surface

Other synonyms of adsorbent include surface-assimilative.

adsorbent (noun)	adsorptive (noun)
a material having capacity or tendency to adsorb another substance

adsorbent (adjective)	adsorptive (adjective)
having capacity or tendency to adsorb or cause to accumulate on a surface	having capacity or tendency to adsorb or cause to accumulate on a surface