Is article a pronoun

No, the Word article is a noun, a singular, common noun; a Word for a piece of writing, an object, a part of a legal document; a Word for a thing.

An article in grammar as a part of speech is a form of determiner used before a noun. The articles are 'the' to indicate a specific person or thing; 'a' to indicate a general person or thing that begins with the sound of a consonant; 'an' to indicate a general person or thing that begins with the sound of a vowel.