This extensive study adequately explores the considerable influence of nickel catalyst and wholly aromatic primarily sulfonated monomers. The synthesis of the chemically and mechanically stable sulfonated poly (phenylenebenzophenone)s (SPPBP) flexible membranes from primarily Sulfonated 1,4-dichloro-2,5-diphenylenebenzophenone (SPBP) and 1,4-dichloro-2,5-diphenylenemethoxybenzophenone (SPMBP) monomers have been reported here using nickel catalyzed carbon-carbon coupling copolymerization. The synthesized SPBP monomer typically possesses a symmetrical structure with excellent reactivity that effectively assisted to control the position, number, and distribution of the sulfonic acid groups in the polymer backbone and attained high molecular weight SPPBP copolymers. The synthesized polymers showed ion exchange capacity (IEC) 1.0-1.93 meqv./g, water uptake 36.4-84.7% and comparable proton conductivity 28.5-94.9 meqv./g to Nafion (R) (98.92 meqv./g) at 90 degrees C. The atomic force microscopic (AFM) results show that SPPBP copolymer membranes provide well phase-separated morphology and thermogravimetric analysis (TGA) confirms the excellent thermal stability of the synthesized SPPBP membranes as well. The synthesized SPPBP membranes possess a potential feature for the practical application in the fuel cell. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.