Renewable and Sustainable Energy Reviews 184 (2023) 113490 Available online 12 July 2023 1364-0321/© 2023 Elsevier Ltd. All rights reserved. Mapping the research landscape of hydrogen production through electrocatalysis: A decade of progress and key trends Talal F. Qahtan a , Ibrahim O. Alade b , Md Safiqur Rahaman c , Tawfik A. Saleh d, * a Physics Department, College of Science and Humanities in Al-Kharj, Prince Sattam Bin Abdulaziz University, 11942, Al-Kharj, Saudi Arabia b Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran, 31261, Saudi Arabia c Deanship of Library Affairs, King Fahd University of Petroleum and Minerals, Dhahran, 31261, Saudi Arabia d Chemistry Department, King Fahd University of Petroleum and Minerals, Dhahran, 31261, Saudi Arabia A R T I C L E INFO Keywords: Electrochemical water splitting Scientometric analysis Hydrogen evolution reaction Oxygen evolution reaction Electrocatalysis Renewable energy ABSTRACT As the demand for renewable energy continues to rise, the significance of electrocatalysis research for hydrogen production has also increased. To explore the developmental trends in this field, a scientometric-assisted review was conducted using clustering analysis of keywords from 43,564 papers published between 2013 and 2022. The results of the study demonstrate a globally diverse research landscape, with contributions from Asia, Europe, North America, and the Middle East. China emerges as the most prolific contributor, with consistent growth in research productivity over the past decade. The USA, South Korea, India, and Germany were among the top five leading countries in electrocatalysis research. Singapore, USA, Australia, Saudi Arabia, and Germany lead research impact, measured by total citations per total paper. China has the highest collaboration in electro- catalysis research, with collaborations with the USA, Australia, Singapore, Saudi Arabia, Japan, the UK, Ger- many, Canada, Korea, and India. Importantly, the study reveals six clusters of electrocatalysis research, with different author keywords, each covering a range of topics and materials. The implications of each of the six clusters in electrocatalysis are examined critically. This study offers valuable insights for researchers, policy- makers, and funding organizations in making critical decisions by identifying the main themes and trends in hydrogen evolution through electrocatalysis research. 1. Introduction The issue of energy sustainability has become more pressing in light of the current global environmental challenges. The burning of fossil fuels is widely acknowledged as a major contributor to climate change, which has resulted in severe consequences such as global warming, flooding, famine, increasingly severe storms, and drought [1–4]. Climate change is a formidable challenge for the survival of humanity, and its pervasive effects have been seen on a global scale [5–7]. In 2019, low-carbon energy sources, which comprise nuclear and renewable sources, contributed only 15.7% of the world’s energy output, while conventional sources such as petroleum oil, coal, and natural gas accounted for almost 85% [8–10]. These conventional energy sources, which are not renewable, have been linked to severe environmental consequences, making the development of sustainable and alternative energy sources an urgent priority [11,12]. Renewable energy sources such as wind, geothermal, tidal, biomass, and solar energy have unlimited potential but are subject to fluctuations in availability due to regional, seasonal, or weather conditions. Thus, effective energy conversion and storage systems are critical for large- scale utilization and continuous supply [13–17]. Hydrogen-based en- ergy storage systems are generating interest as a cost-effective strategy for large-scale storage, transportation, and utilization of renewable en- ergy [18]. Storing the excess renewable energy in an energy carrier such as hydrogen that can be stored, transported, and utilized is one clever approach to resolve the renewable energy storage challenge [19,20]. Electricity-driven electrolytic water splitting is a promising strategy that can utilize the excess amount of energy from renewable energy sources for hydrogen production. It is a well-established facile and green route that is used for the generation of hydrogen and oxygen by water splitting [21,22]. However, the cost of electricity associated with elec- trolytic hydrogen is one of its demerits, covering close to 80% of the operation cost. Nonetheless, excess energy from renewable sources could be used for hydrogen production via the electrolysis process. It * Corresponding author. E-mail address: tawfikas@hotmail.com (T.A. Saleh). Contents lists available at ScienceDirect Renewable and Sustainable Energy Reviews journal homepage: www.elsevier.com/locate/rser https://doi.org/10.1016/j.rser.2023.113490 Received 7 December 2022; Received in revised form 12 June 2023; Accepted 21 June 2023