TY - JOUR
T1 - Influence of mixing time on a reversal tolerant anode measured ex situ for a PEMFC
AU - Homan, S. J.T.
AU - Aylar, K.
AU - Jurjevic, A.
AU - Scolari, M.
AU - Urakawa, A.
AU - Taheri, P.
PY - 2024
Y1 - 2024
N2 - When no hydrogen can reach the Pt catalyst in the anode for the hydrogen oxidation reaction (HOR) of an operating proton exchange membrane fuel cell (PEMFC), the anode potential increases and causes the cell potential to be reversed compared to normal operation conditions. During this reversal, the oxygen evolution reaction (OER) and carbon oxidation reaction (COR) will occur at the anode, where the COR has devastating consequences for the electrode. Introducing an OER catalyst limits the COR to occur, which makes a reversal tolerant anode (RTA). In this research, RTAs are differentiated by applying different ball milling times during catalyst layer processing, forming big and small OER (IrOx/TiOx) and HOR (Pt/C) catalyst particles. The two different particle sizes were electrochemically tested using a rotating disc electrode (RDE). Both catalyst sizes show a decrease in OER activity (mA cm−2) accompanied by loss of the ionomer in a self-developed accelerated stress test (AST). The small particle RTAs show higher OER activity as a result of increased surface area. However, during a chronopotentiometry measurement, which mimics a fuel cell reversal, the small particle coatings show a worse reversal tolerance. This phenomenon can be attributed to the increased difficulty in removing oxygen bubbles.
AB - When no hydrogen can reach the Pt catalyst in the anode for the hydrogen oxidation reaction (HOR) of an operating proton exchange membrane fuel cell (PEMFC), the anode potential increases and causes the cell potential to be reversed compared to normal operation conditions. During this reversal, the oxygen evolution reaction (OER) and carbon oxidation reaction (COR) will occur at the anode, where the COR has devastating consequences for the electrode. Introducing an OER catalyst limits the COR to occur, which makes a reversal tolerant anode (RTA). In this research, RTAs are differentiated by applying different ball milling times during catalyst layer processing, forming big and small OER (IrOx/TiOx) and HOR (Pt/C) catalyst particles. The two different particle sizes were electrochemically tested using a rotating disc electrode (RDE). Both catalyst sizes show a decrease in OER activity (mA cm−2) accompanied by loss of the ionomer in a self-developed accelerated stress test (AST). The small particle RTAs show higher OER activity as a result of increased surface area. However, during a chronopotentiometry measurement, which mimics a fuel cell reversal, the small particle coatings show a worse reversal tolerance. This phenomenon can be attributed to the increased difficulty in removing oxygen bubbles.
KW - Catalyst layer processing
KW - OER catalyst
KW - PEMFC
KW - Reversal tolerant anode (RTA)
KW - Rotating disc electrode (RDE)
UR - http://www.scopus.com/inward/record.url?scp=85187282265&partnerID=8YFLogxK
U2 - 10.1016/j.ijhydene.2024.01.236
DO - 10.1016/j.ijhydene.2024.01.236
M3 - Article
AN - SCOPUS:85187282265
SN - 0360-3199
VL - 59
SP - 1166
EP - 1173
JO - International Journal of Hydrogen Energy
JF - International Journal of Hydrogen Energy
ER -