Short communication Low platinum loading for high temperature proton exchange membrane fuel cell developed by ultrasonic spray coating technique Huaneng Su, Ting-Chu Jao * , Olivia Barron, Bruno G. Pollet, Sivakumar Pasupathi HySA Systems Competence Centre, South African Institute for Advanced Materials Chemistry (SAIAMC), University of the Western Cape, Robert Sobukwe Road, Bellville 7535, Cape Town, South Africa highlights  Low Pt loading GDEs were first inspected for HT-PEMFC.  Four different Pt loadings (from 0.138 to 1.208 mg cm 2 ) were investigated.  The optimal Pt loading was found to be 0.350 mg cm 2 .  The peak cathode mass power is as high as 0.967 W mg Pt 1 . article info Article history: Received 24 February 2014 Received in revised form 13 May 2014 Accepted 17 May 2014 Available online 27 May 2014 Keywords: Low Pt loading Proton exchange membrane fuel cell High temperature Membrane electrode assembly Poly(2,5-benzimidazole) Ultrasonic spray coating abstract This paper reports use of an ultrasonic-spray for producing low Pt loadings membrane electrode as- semblies (MEAs) with the catalyst coated substrate (CCS) fabrication technique. The main MEA sub- components (catalyst, membrane and gas diffusion layer (GDL)) are supplied from commercial manu- facturers. In this study, high temperature (HT) MEAs with phosphoric acid (PA)-doped poly(2,5- benzimidazole) (ABePBI) membrane are fabricated and tested under 160  C, hydrogen and air feed 100 and 250 cc min 1 and ambient pressure conditions. Four different Pt loadings (from 0.138 to 1.208 mg cm 2 ) are investigated in this study. The experiment data are determined by in-situ electro- chemical methods such as polarization curve, electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The high Pt loading MEA exhibits higher performance at high voltage operating conditions but lower performances at peak power due to the poor mass transfer. The Pt loading 0.350 mg cm 2 GDE performs the peak power density and peak cathode mass power to 0.339 W cm 2 and 0.967 W mg Pt 1 , respectively. This work presents impressive cathode mass power and high fuel cell performance for high temperature proton exchange membrane fuel cells (HT-PEMFCs) with low Pt loadings. © 2014 Elsevier B.V. All rights reserved. 1. Introduction Due to the high power density, high efficiency, zero emissions, high-quality power, scalability and fast start-up, proton exchange membrane fuel cells (PEMFCs) are considered as promising future power sources [1]. High temperature proton exchange membrane fuel cell (HT- PEMFC) is a relatively new research area which has gained considerable interest recently with over 2000 research articles published since 2012. Among these researches, phosphoric acid (PA)-doped polybenzimidazole (PBI) system is considered as the most promising candidate for HT-PEMFC with the capability of operating up to 200  C [2e5]. Important properties, e.g. the proton conductivity of and the conduction mechanism in the membranes [6e11], their mechanical properties and gas permeability as well as the development of membrane electrode assemblies (MEAs) based on this type of membrane and their electrochemical performance at various operating conditions have been studied extensively [4,5,12e15]. The high operating temperature of this PA-doped PBI- based fuel cell system offers several advantages: (i) no need for water management systems, (ii) high tolerance for fuel impurities (up to 3% CO in the fuel stream enabling the use of a simple reformer system), (iii) high quality heat that can be utilized for cogeneration purposes, (iv) simplified Flow Field Plate (FFP) design due to improved transport of vapour water in the structures, (v) minimized BoP requirements in turns allowing simpler system designs [16]. * Corresponding author. Tel./fax: þ27 21 959 9310. E-mail address: s968706@gmail.com (T.-C. Jao). Contents lists available at ScienceDirect Journal of Power Sources journal homepage: www.elsevier.com/locate/jpowsour http://dx.doi.org/10.1016/j.jpowsour.2014.05.086 0378-7753/© 2014 Elsevier B.V. All rights reserved. Journal of Power Sources 267 (2014) 155e159