Phosphomolybdic acid dispersed in the micropores of Al-pillared clay (PMA/Al-PILC) was prepared by the impregnation method and characterized by XRD and sorptomeric studies. The interlayer structure of the Al-pillared clay was found to be retained in the PMA/Al-PILC catalyst which displays high surface area and micropore volume. The PMA/Al-PILC material was used as a heterogeneous and recyclable catalyst for efficient condensation of beta-naphthol with arylaldehydes to afford a variety of structurally diverse aryl-14H-dibenzo[a,j]xanthenes in excellent yield and purity in short reaction time under microwave irradiation.