1 State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China 2 Clean Energy Automotive Engineering Center, Tongji University, Shanghai 201804, China 3 College of Automotive Studies, Tongji University, Shanghai 201804, China
In order to increase the utilization of the precious metal catalysts in proton exchange membrane fuel cells, a new type of Pt/buckypaper catalytic layer with gradient structure was designed and prepared. Carbon nanotubes (CNTs) pretreated using ultrasonic method in mixed acid were used as the support of Pt catalyst. The Pt/buckypaper catalytic layer with Pt/CNTs gradient distribution was fabricated by simple filtration method. Several techniques such as scanning electron microscope, energy-dispersive X-ray spectroscope were utilized to characterize the microstructure and morphology of the catalyst and catalytic layer as well as the Pt distribution. The electrocatalytic performance of the catalyst and catalytic layer were measured by cyclic voltammetry and linear sweep voltammetry methods. The results show that the Pt particles were well dispersed on the CNTs support and the Pt particle size of Pt/CNTs was about 2.4nm. The electrochemical specific area (ECSA) of Pt/CNTs is similar to that of commercial Pt/C catalyst, while its specific mass activity and electrochemical stability were much higher than those of Pt/C. The ECSA of Pt/buckypaper catalytic layer can basically maintain the value of Pt/CNTs, indicating a high utilization of Pt. The novel gradient structure of catalytic layer manifests its promising applications in fuel cells.
BALL M , WIETSCHEL M . The future of hydrogen-opportunities and challenges[J]. International Journal of Hydrogen Energy, 2009, 34 (2): 615- 627.
AMBROSIO E P , FRANCIA C , MANZOLI M , et al. Platinum catalyst supported on mesoporous carbon for PEMFC[J]. International Journal of Hydrogen Energy, 2008, 33 (12): 3142- 3145.
STEVENS D A , HICKS M T , HAUGEN G M , et al. Ex situ and in situ stability studies of PEMFC catalysts effect of carbon type and humidification on degradation of the carbon[J]. Journal of the Electrochemical Society, 2005, 152 (12): A2309- A2315.
WU G , MORE K L , JOHNSTON C M , et al. High-performance electrocatalysts for oxygen reduction derived from polyaniline, iron, and cobalt[J]. Science, 2011, 332 (6028): 443- 447.
ZHENG J S , TIAN T , GAO Y , et al. Ultra-low Pt loading catalytic layer based on buckypaper for oxygen reduction reaction[J]. International Journal of Hydrogen Energy, 2014, 39 (25): 13816- 13823.
YE L C , GAO Y , ZHENG J S , et al. Preparation of Pt/buckypaper by surface modified multi-walled carbon nanotubes for oxygen reduction reaction in PEMFCs[J]. Ecs Transactions, 2015, 66 (13): 1- 9.
ZHU W , ZHENG J P , LIANG R , et al. Ultra-low platinum loading high-performance PEMFCs using buckypaper-supported electrodes[J]. Electrochemistry Communications, 2010, 12 (11): 1654- 1657.
ZHU W , KU D , ZHENG J P , et al. Buckypaper-based catalytic electrodes for improving platinum utilization and PEMFC's performance[J]. Electrochimica Acta, 2010, 55 (7): 2555- 2560.
CHEN S , YE F , LIN W . Carbon nanotubes-Nafion composites as Pt-Ru catalyst support for methanol electro-oxidation in acid media[J]. Journal of Natural Gas Chemistry, 2009, 18 (2): 199- 204.
LIMA F H B , ZHANG J , SHAO M H , et al. Catalytic activity-d-band center correlation for the O2 reduction reaction on platinum in alkaline solutions[J]. Journal of Physical Chemistry C, 2006, 111 (1): 404- 410.
WANG S , JIANG S P , WHITE T J , et al. Electrocatalytic activity and interconnectivity of Pt nanoparticles on multi-walled carbon nanotubes for fuel cells[J]. Journal of Physical Chemistry C, 2009, 113 (43): 18935- 18945.
DENG L F , PENG H Y , QIN Y K , et al. Combination carbon nanotubes with graphene modified natural graphite and its electrochemical performance[J]. Journal of Materials and Engineering, 2017, 45 (4): 121- 127.
KHARISOV B I , KHARISSOVA O V , GUTIERREZ H L , et al. Recent advances on the soluble carbon nanotubes[J]. Industrial & Engineering Chemistry Research, 2008, 48 (2): 572- 590.
TASIS D , TAGMATARCHIS N , GEORGAKILAS V , et al. Soluble carbon nanotubes[J]. Chemistry, 2003, 9 (43): 4000- 4008.
RODRÍGUEZ-REINOSO F . The role of carbon materials in heterogeneous catalysis[J]. Carbon, 1998, 36 (3): 159- 175.
SONG L , CHEN J Q , FAN W X , et al. Influencing mechanism of electrochemical treatment on preparation of CNTs-grafted on carbon fibers[J]. Journal of Materials and Engineering, 2017, 45 (11): 15- 22.
LIANG S , LI G , TIAN R . Multi-walled carbon nanotubes functionalized with a ultrahigh fraction of carboxyl and hydroxyl groups by ultrasound-assisted oxidation[J]. Journal of Materials Science, 2016, 51 (7): 3513- 3524.
GUITTONNEAU F , ABDELOUAS A , GRAMBOW B , et al. The effect of high power ultrasound on an aqueous suspension of graphite[J]. Ultrasonics Sonochemistry, 2010, 17 (2): 391- 8.
XING Y . Synthesis and electrochemical characterization of uniformly-dispersed high loading Pt nanoparticles on sonochemically-treated carbon nanotubes[J]. Journal of Physical Chemistry B, 2004, 108 (50): 19255- 19259.
YANG C W , HU X G , ZHANG L , et al. Study of functionalization on multi-wall carbon nanotubes by ultrasound[J]. Journal of Materials and Engineering, 2008, (7): 79- 82.
CHEN Y , WANG J , LIU H , et al. Nitrogen doping effects on carbon nanotubes and the origin of the enhanced electro-catalytic activity of supported Pt for proton-exchange membrane fuel cells[J]. Journal of Physical Chemistry C, 2011, 115 (9): 3769- 3776.
LU C Y , WEI M C , CHANG S H , et al. Study of the activity and backscattered electron image of Pt/CNTs prepared by the polyol process for flue gas purification[J]. Applied Catalysis A General, 2009, 354 (1): 57- 62.
CHEN Y , WANG J , LIU H , et al. Enhanced stability of Pt electrocatalysts by nitrogen doping in CNTs for PEM fuel cells[J]. Electrochemistry Communications, 2009, 11 (10): 2071- 2076.
LEE K , ZHANG J , WANG H , et al. Progress in the synthesis of carbon nanotube-and nanofiber-supported Pt electrocatalysts for PEM fuel cell catalysis[J]. Journal of Applied Electrochemistry, 2006, 36 (5): 507- 522.
SUÁREZ-ALCÁNTARA K , SOLORZA-FERIA O . Kinetics and PEMFC performance of RuxMoySez nanoparticles as a cathode catalyst[J]. Electrochimica Acta, 2008, 53 (15): 4981- 4989.
GASTEIGER H A , KOCHA S S , SOMPALLI B , et al. Activity benchmarks for Pt, Pt-alloy and non-Pt oxygen reduction catalysts for PEMFCs[J]. Applied Catalysis B:Environmental, 2005, 56 (1): 9- 35.
WANG Y , ZENG X A , LIU H , et al. Effect of preparation conditions of catalyst ink on the electrochemical properties of Pt/C catalyst[J]. Chinese Journal of Catalysis, 2011, 32 (1): 184- 188.
WANG L , YANG C , DOU S , et al. Nitrogen-doped hierarchically porous carbon networks:synthesis and applications in lithium-ion battery, sodium-ion battery and zinc-air battery[J]. Electrochimica Acta, 2016, 219, 592- 603.