TY - JOUR
T1 - Analysis of ammonia electro-oxidation kinetics using a rotating disk electrode
AU - Diaz, Luis A.
AU - Valenzuela-Muñiz, Ana
AU - Muthuvel, Madhivanan
AU - Botte, Gerardine G.
N1 - Funding Information:
The authors would like to thank the financial support of the Center for Electrochemical Engineering Research (CEER) at Ohio University and the Department of Defense through the U.S. Army Construction Engineering Research Laboratory ( W9132T-09-1-0001 ). The content of the information does not reflect the position or the policy of the U.S. government. Authors also thank the Institute for Corrosion and Multiphase Technology (ICMT) at Ohio University, for the use of the SEM equipment, and the facilities at CEER.
PY - 2013/2/1
Y1 - 2013/2/1
N2 - The kinetics for the electro-oxidation of ammonia in alkaline media was revisited by utilizing a rotating disk electrode (RDE) system. A well-characterized electrocatalyst for the oxidation of ammonia was developed by electrodepositing platinum over a nickel disk electrode in alkaline media at different deposition temperatures (50, 60, and 70 °C) and times (20, 40, and 80 min). The catalyst prepared by the deposition of Pt at 50 °C for 80 min over a Ni disk electrode was found to be the better electrocatalyst for the ammonia oxidation process. This electrode was used in the RDE assembly and subjected to the linear sweep voltammetry experiments to investigate the kinetics of the electro-oxidation of ammonia. The results based on the studies from varying rotational speeds (0-2000 rpm) and scan rates (1-90 mV s -1) indicated that the ammonia electro-oxidation was controlled by mass transfer limitations. A dimensionless analysis illustrated that the presence of an oxidation peak even at high rotational speed in the current-voltage curve could be explained by a transient current response induced by the mass transfer limitations.
AB - The kinetics for the electro-oxidation of ammonia in alkaline media was revisited by utilizing a rotating disk electrode (RDE) system. A well-characterized electrocatalyst for the oxidation of ammonia was developed by electrodepositing platinum over a nickel disk electrode in alkaline media at different deposition temperatures (50, 60, and 70 °C) and times (20, 40, and 80 min). The catalyst prepared by the deposition of Pt at 50 °C for 80 min over a Ni disk electrode was found to be the better electrocatalyst for the ammonia oxidation process. This electrode was used in the RDE assembly and subjected to the linear sweep voltammetry experiments to investigate the kinetics of the electro-oxidation of ammonia. The results based on the studies from varying rotational speeds (0-2000 rpm) and scan rates (1-90 mV s -1) indicated that the ammonia electro-oxidation was controlled by mass transfer limitations. A dimensionless analysis illustrated that the presence of an oxidation peak even at high rotational speed in the current-voltage curve could be explained by a transient current response induced by the mass transfer limitations.
KW - Ammonia electro-oxidation
KW - Mathematical modeling
KW - Pt catalyst
KW - Rotating disk electrode
KW - Transient current
UR - http://www.scopus.com/inward/record.url?scp=84874400423&partnerID=8YFLogxK
U2 - 10.1016/j.electacta.2012.11.064
DO - 10.1016/j.electacta.2012.11.064
M3 - Article
AN - SCOPUS:84874400423
VL - 89
SP - 413
EP - 421
JO - Electrochimica Acta
JF - Electrochimica Acta
SN - 0013-4686
ER -