Progress and framework of clean energy production: Bibliometric analysis from 2002 to 2022

Current society prioritizes clean energy production (CEP) to meet diverse energy needs and achieve sustainability. Current research involves different aspects of CEP, but comprehensive research is limited. Therefore, this paper aims to improve researchers' integrated understanding of the field and reveal the significant research trends by using CiteSpace to conduct a visualized bibliometric analysis of CEP in the past 20 years. Specifically, we aim to analyze the statistical characteristics, collaboration dynamics, research status, and hotspot evolutions; we find that CEP is an increasingly focused hot field, with Asian institutions and countries are more active collaborators; besides, most highly co-cited journals have high impact factors and reputations, and they are related to physics, chemistry, and biology; furthermore, the hot topics cover the whole procedure of CEP and have been changing significantly over the 20 years; in the future, research will integrate more disciplines, new topics may occur, and the research paradigm will be more collaborative, targeting specific segments and engineering application-oriented. The most important trends in the future are renewable energy, lignocellulosic biomass, carbon capture, and CEP challenges. The results help scholars understand this field's knowledge more comprehensively, effectively, and efficiently.