DOI: https://doi.org/10.55373/mjchem.v28i4.216

Keywords: Sulfonated PEEK, Functionalization, Proton exchange membrane, Bibliometric analysis, PEMFC

Abstract

The development of efficient proton exchange membranes (PEMs) is critical for advancing fuel cell technologies, where sulfonated poly(ether ether ketone) (SPEEK) has emerged as a promising alternative to conventional perfluorosulfonic acid (PFSA) membranes. Hence, a systematic quantitative overview of global research on SPEEK functionalization is pressingly required. This study, therefore, conducts a bibliometric analysis of SPEEK-based PEMs research from 2005 to 2025 to evaluate its scientific development, structure, and emerging trends. The results presented strong and continuous growth in publications, particularly after 2015, indicating increasing global interest in SPEEK functionalization. The field is highly collaborative, with an average of 5.75 co-authors per document and a high citation impact (38.43 citations per document). Research output is concentrated in key journals such as the International Journal of Hydrogen Energy, Journal of Membrane Science, and Journal of Power Sources. China is the leading contributor, followed by India, Korea, Iran, and Malaysia. Thematic evolution indicates a shift from conventional SPEEK membranes toward multifunctional nanocomposite systems with improved durability and performance. Overall, the findings from the study offer valuable insights into research hotspots and future directions for developing high-performance proton exchange membranes for fuel cell applications.