catalysts Editorial Top 10 Cited Papers in the Section “Electrocatalysis” Vincenzo Baglio Institute for Advanced Energy Technologies “Nicola Giordano”—CNR-ITAE, Via Salita S. Lucia sopra Contesse 5, 98126 Messina, Italy; vincenzo.baglio@itae.cnr.it Received: 13 November 2020; Accepted: 24 November 2020; Published: 25 November 2020   This editorial is dealing with the most cited papers published in the years 2018–2019 in the section “Electrocatalysis” of the journal Catalysts. They are mainly review papers, but regular research articles and communications are also present in this analysis. The main topics appear related to the reactions/processes occurring in fuel cells and electrolysers, i.e., oxygen reduction, oxygen evolution, hydrogen evolution, hydrogen oxidation, with the only exception being a paper dealing with electrochemical sensing performance toward dopamine. The paper collecting the highest number of citations is a review paper of H. Zhong et al. [1], which analyzes the advances in the development of cobalt-based catalytic centers as the most potentially useful alternatives to noble metal-based electrocatalysts (Pt-, Ir-, and Ru-based) towards the oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and hydrogen evolution reaction (HER) in acid and alkaline media. The Co-based catalysts are categorized into five groups, namely, cobalt chalcogenides (selenides, sulfides), cobalt oxides, Co–LDH, Co–MOFs, and Co–N x /C. Synthetic strategies, structural properties, defects, and support materials are discussed as a function of the electrocatalytic performance of cobalt-based electrocatalysts, together with the perspectives for large-scale application of these materials. Another review paper dealing with electrocatalysis for the oxygen reduction reaction (ORR) [2] received great attention due to the important application in fuel cells and metal–air batteries. The high cost of noble metal hinders the commercialization of the above-mentioned devices. Therefore, developing efficient and cost-effective catalysts is of vital importance. This work summarizes the recent progress of nitrogen (N)-doped metal-free catalysts for the ORR and provides future perspectives for their further development. The effect of metal doping on Ni-based electrocatalysts for hydrogen oxidation was investigated by E. S. Davydova et al. [3]. Ni–TM/C (where TM stands for the doping elements Fe, Co, and Cu) electrocatalytic composites were synthesized via the chemical reduction method, and physico-chemically characterized by using different techniques. The electrochemical properties towards hydrogen oxidation reaction in alkaline medium were studied using the rotating disc electrode and cycling voltammetry methods, revealing a significant role of the TM dopants in the promotion of the hydrogen electrooxidation kinetics of the binary Ni–TM/C materials. Another review paper analyzes the ORR, but in this case it summarizes the efforts employing Pt, Au, Ag, Pd and Ru clusters, as well as the alloyed bi-metallic clusters for acquiring highly efficient catalysts to enhance both the activity and stability [4]. The current challenges, the future outlook, and the perspectives will be proposed, featuring the great opportunities and potentials to engineering noble metal clusters as highly efficient and durable cathodic catalysts for fuel cell applications. Only one article in this top-10 list of most cited papers is not dealing with reactions/processes occurring in electrochemical energy conversion and storage devices. In this work, the morphology- dependent electrochemical sensing properties of MnO 2 -reduced graphene oxide/glass carbon electrode (MnO 2 -RGO/GCE) toward dopamine detection were investigated [5]. Different morphologies of nanoscale MnO 2 were synthesized under different hydrothermal conditions. Successively, the MnO 2 - Catalysts 2020, 10, 1378; doi:10.3390/catal10121378 www.mdpi.com/journal/catalysts