Arabian Journal for Science and Engineering https://doi.org/10.1007/s13369-018-3368-y RESEARCH ARTICLE - CHEMICAL ENGINEERING Studies on an Ultrasonic Synthesis, Characterization, and Thermodynamic Analysis of New Metal Nanocatalysts Applied Directly to Alcohol Fuel Cells Bahdi¸ sen Gezer 1 Received: 22 November 2017 / Accepted: 31 May 2018 © King Fahd University of Petroleum & Minerals 2018 Abstract In this study, for direct methanol fuel cell (DMFC), PtCu and PtOs nanocatalysts were prepared using the ultrasound-assisted method to directly enhance methanol fuel cell (DMFC) performance. Ultrasonic applications are safe from laboratory to industry and from environmental impacts on energy applications. It was aimed to strengthen Pt/Cu and Pt/Os dispersion with platinum nanocatalyst directly stabilized by copper (Cu) and osmium (Os) ligands and to increase active surface area by using ultrasonication method. Then, these prepared monodisperse nanomaterials for characterization techniques have been used as X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, and induced paired plasma optical emission spectrometry. The results obtained show that methanol crossover has been found to decrease significantly when reaching the value of the large stable open-circuit voltage of the DMFC under the ultrasound-assisted system. Polarization performance does not change significantly. For this reason, in an ultrasound-assisted process, increased energy density of DMFC in high methanol concentration improves operating performance. The membrane electrode assembly having PtOs and PtCu provided the highest performance with the peak power density of 0.582 and 0.489 mW/cm 2 at a temperature of 120 ◦ C and concentration methanol of 4 M, respectively. Based on the results of the stability tests, a commercial cathode catalyst was developed from PtCu and PtOs. Keywords Direct alcohol fuel cell · Ultrasound assisted · New nanocatalyst 1 Introduction Energy is known to be the most important consumption mate- rial of our time and it causes increasing energy demand due to increasing population, urbanization and industrialization. This ensures that energy becomes even more important. A large majority of the energy currently used is from fossil fuels such as coal, oil, and natural gas. But environmental problems such as global warming and air pollution caused by these fossil fuels, as well as the fact that these resources will be exhausted one day, have forced people to search for new energy sources. For this reason, many alternative energy sources such as wind energy, solar energy, and fuel cells have come to the forefront as renewable energy sources of clean energy [1]. It significantly helps to reduce the adverse B Bahdi¸ sen Gezer bahdisen.gezer@usak.edu.tr 1 Department of Electrical and Electronics Engineering, Engineering Faculty,U¸ sak University, 38000 U¸ sak, Turkey environmental impact of fuels in energy conversion systems based on direct burning of fossil fuels [2]. Fuel batteries are seen as the right choice to get electricity with their distinctive features such as being more efficient and making less noise. But the biggest disadvantage of fuel pellets is the price prob- lem, because of the dependability of electrochemical cells [3,4]. The majority of fuel pellets are used as hydrogen and alcohol fuel [5]. For this reason, studies on the use of fuel cells in vehicles and other portable electronic devices con- tinue [6]. Direct methanol fuel cells (DMFCs) have become of great interest recently owing to their high energy density and easy storage of liquid methanol fuel [7,8]. Catalysts are often needed to derive the main core of DMFC technology, espe- cially from the standpoint of stationary methanol oxidation reactions (MORs) and oxygen reduction reactions (ORRs) [9,10]. There are many active investigations involving the development and testing of DMFCs using different materials and production techniques (e.g., [11,12]). The main objective 123