TY - JOUR
T1 - CeOx-functionalized Pd nanoparticles on single-walled carbon nanotubes for alkaline hydrogen oxidation reaction
AU - Ali, Farhan S.M.
AU - Lucchetti, Lanna E.B.
AU - Hammouali, Med Amine
AU - Rautama, Eeva-Leena
AU - Sainio, Jani
AU - Jiang, Hua
AU - Moumaneix, Lilian
AU - Kallio, Antti-Jussi
AU - Sorsa, Olli
AU - Huotari, Simo
AU - Singh, Ramesh K.
AU - Dekel, Dario R.
AU - Siahrostami, Samira
AU - Kallio, Tanja
PY - 2026/2/1
Y1 - 2026/2/1
N2 - The sluggish kinetics of hydrogen oxidation reaction (HOR) in alkaline electrolytes highlight the strong need to develop next-generation catalyst materials for anion-exchange membrane fuel cells (AEMFC) anodes. In this study, CeOx is sequentially deposited on Pd nanoparticles supported on single-walled carbon nanotubes (SWNT) via atomic layer deposition (ALD). The obtained Pd@CeOx SWNT16 ALD cycles catalyst shows an excellent alkaline HOR performance with a specific exchange current of 166 mA mg−1Pd. This is three times higher than the commercially available Pd catalyst and the highest among reported Pd/CeOx catalyst materials with different CeOx overlayer coverages. By combining the X-ray diffraction, X-ray photoelectron spectroscopy, X-ray absorption spectroscopy and high-resolution scanning transmission electron microscopy, we confirm that the activity improvement is due to the highly conductive SWNT support enabling the fabrication of high surface area Pd clusters and CeOx overlayer. These methods reveal that the oxidation state of Ce is varying from Ce3+ to Ce4+ in relation to the CeOx overlayer thickness and the number of ALD cycles. Density functional theory calculations show that the presence of Ce/CeOx increases the diversity and population of Pd active sites with improved activity in its vicinity leading to enhanced overall catalytic performance. Moreover, this work provides a new perspective to develop highly active alkaline HOR catalysts for AEMFC.
AB - The sluggish kinetics of hydrogen oxidation reaction (HOR) in alkaline electrolytes highlight the strong need to develop next-generation catalyst materials for anion-exchange membrane fuel cells (AEMFC) anodes. In this study, CeOx is sequentially deposited on Pd nanoparticles supported on single-walled carbon nanotubes (SWNT) via atomic layer deposition (ALD). The obtained Pd@CeOx SWNT16 ALD cycles catalyst shows an excellent alkaline HOR performance with a specific exchange current of 166 mA mg−1Pd. This is three times higher than the commercially available Pd catalyst and the highest among reported Pd/CeOx catalyst materials with different CeOx overlayer coverages. By combining the X-ray diffraction, X-ray photoelectron spectroscopy, X-ray absorption spectroscopy and high-resolution scanning transmission electron microscopy, we confirm that the activity improvement is due to the highly conductive SWNT support enabling the fabrication of high surface area Pd clusters and CeOx overlayer. These methods reveal that the oxidation state of Ce is varying from Ce3+ to Ce4+ in relation to the CeOx overlayer thickness and the number of ALD cycles. Density functional theory calculations show that the presence of Ce/CeOx increases the diversity and population of Pd active sites with improved activity in its vicinity leading to enhanced overall catalytic performance. Moreover, this work provides a new perspective to develop highly active alkaline HOR catalysts for AEMFC.
U2 - 10.1016/j.carbon.2026.121313
DO - 10.1016/j.carbon.2026.121313
M3 - Article
SN - 0008-6223
VL - 250
SP - 121313
JO - Carbon
JF - Carbon
ER -