Electrocatalytic “Volcano-Type” Effect of Nano-TiO₂ (A)/(R) Phase Content in Pt/TiO₂-CN_x Catalyst

Abstract

The relationship between the electrochemical activity of fuel cell catalysts and Pt particle size, as well as the catalyst support and co-catalyst is still unclear. In this work, FESEM, XRD, BET, TEM and CV techniques were adopted to investigate the effects of TiO₂ anatase (A)/rutile (R) phases content on the electrochemical activity of Pt electrocatalyst. The results showed that the anatase-rutile phase transformation occurred during the heat treatment of TiO₂ at 700 ~ 900 ^oC accompanied by the growth of two-phase crystalline size, and anatase was completely transformed into rutile at 900 ^oC. TEM results revealed that the ultrafine Pt electrocatalysts with the particle size of 1.8 ~ 2.8 nm were successfully prepared over the TiO₂-CN_x supports. The content of TiO₂ (A)/(R) phases had a “volcano-type” effect on both the BET surface area of TiO₂-CN_x supports and the real “effective” electrochemical active surface area (ECSA) of Pt/TiO₂-CN_x catalysts. When the rutile content was 25%, the TiO₂(25%R)-CN_x support and Pt/TiO₂(25%R)-CN_x catalyst had the largest specific surface area and the most electrochemical active sites, respectively. It is speculated that raising the rutile content, there might be a strong metal-support interaction between Pt nanoparticles and TiO₂(25%R)-CN_x support with the rutile content of 25%, which could anchor the ultrafine Pt nanoparticles, resulting in the highest ECSA of Pt/TiO₂(25%R)-CN_x catalyst. Therefore, the Pt/TiO₂(25%R)-CN_x became more suitable as a catalyst for fuel cells.

Keywords

catalyst / TiO₂ / anatase / rutile / electrochemical active surface area

References

[1] Liao J H, Ding W, Tao S C, Nie Y, Li W, Wu G P, Chen S G, Li L, Wei Z D. Carbon supported IrM (M = Fe, Ni, Co) alloy nanoparticles for the catalysis of hydrogen oxidation in acidic and alkaline medium[J]. Chinese J. Catal., 2016, 37(7): 1142-1148.

[2] Lin R B, Shih S M. Effects of mass transfer on kinetics of hydrogen oxidation reaction at Nafion/Pt-black thin-film electrodes[J]. J. Taiwan Inst. Chem. E., 2013, 44(3): 393-401.

[3] Babić B M, Vračar L M, Radmilović V, Krstajić N V. Carbon cryogel as support of platinum nano-sized electrocatalyst for the hydrogen oxidation reaction[J]. Electrochim. Acta, 2006, 51(18): 3820-3826.

[4] Serrano-Ruiz J C, López-Cudero A, Solla-Gullón J, Sepúl-veda-Escribano A, Aldaz A, Rodríguez-Reinoso F. Hydrogenation of α, β unsaturated aldehydes over polycrystalline, (111) and (100) preferentially oriented Pt nanoparticles supported on carbon[J]. J. Catal., 2008, 253(1): 159-166.

[5] Calvillo L, Lázaro M J, García-Bordejé E, Moliner R, Cabot P L, Esparbé I, Pastor E, Quintana J J. Platinum supported on functionalized ordered mesoporous carbon as electrocatalyst for direct methanol fuel cells[J]. J. Power Sources, 2007, 169(1): 59-64.

[6] Hayden B E. Particle size and support effects in electrocatalysis[J]. Accounts Chem. Res., 2013, 46(8): 1858-1866.

[7] Rodgers M P, Bonville L J, Kunz H R, Slattery D K, Fenton J M. Fuel cell perfluorinated sulfonic acid membrane degradation correlating accelerated stress testing and lifetime[J]. Chem. Rev., 2012, 112(11): 6075-6103.

[8] Tripković V, Abild-Pedersen F, Studt F, Cerri I, Nagami T, Bligaard T, Rossmeisl J. Metal oxide-supported platinum overlayers as proton-exchange membrane fuel cell cathodes[J]. ChemCatChem, 2012, 4(2): 228-235.

[9] Jia J C, Wang H, Ji S, Yang H J, Li X S, Wang R F. SnO₂-embedded worm-like carbon nanofibers supported Pt nanoparticles for oxygen reduction reaction[J]. Electrochim. Acta. 2014, 141: 13-19.

[10] Wang Y J, Wilkinson D P, Zhang J J. Noncarbon support materials for polymer electrolyte membrane fuel cell electrocatalysts[J]. Chem. Rev., 2011, 111(12): 7625-7651.

[11] Zhao X, Zhu J B, Liang L, Liao J H, Liu C P, Xing W. Enhanced activity of Pt nano-crystals supported on a novel TiO₂@N-doped C nano-composite for methanol oxidation reaction[J]. J. Mater. Chem., 2012, 22(37): 19718-19725.

[12] Li Z H, Yang K, Liu G, Deng G F, Li J Q, Li G, Yue R L, Yang J, Chen Y F. Effect of reduction treatment on structural properties of TiO₂ supported Pt nanoparticles and their catalytic activity for benzene oxidation[J]. Catal. Lett., 2014, 144(6): 1080-1087.

[13] Chung S L, Wang C M. A sol-gel combustion synthesis method for TiO₂ powders with enhanced photocatalytic activity[J]. J. Sol-Gel Sci. Techn., 2011, 57(1): 76-85.

[14] von Kraemer S, Wikander J, Lindbergh G, Lundblad A, Palmqvist A E C. Evaluation of TiO₂ as catalyst support in Pt-TiO₂/C composite cathodes for the proton exchange membrane fuel cell[J]. J. Power Sources, 2008, 180(1): 185-190.

[15] Qin Y H, Li Y F, Lv R L, Wang T L, Wang W G, Wang C W. Enhanced methanol oxidation activity and stability of Pt particles anchored on carbon-doped TiO₂ nanocoating support[J]. J. Power Sources, 2015, 278: 639-644.

[16] Antoniassi R M, Quiroz J, Barbosa E C M, Parreira L S, Isidoro R A, Spinacé E V, Silva J C M, Camargo P H C. Improving the electrocatalytic activities and CO tolerance of Pt NPs by incorporating TiO₂ nanocubes onto carbon supports[J]. ChemCatChem, 2021, 13(8): 1931-1939.

[17] Stühmeier B M, Selve S, Patel M U M, Geppert T N, Gasteiger H A, El-Sayed H A. Highly selective Pt/TiO_x catalysts for the hydrogen oxidation reaction[J]. ACS Appl. Energy Mater., 2019, 2(8): 5534-5539.

[18] Connelly K, Wahab A K, Idriss H. Photoreaction of Au/TiO₂ for hydrogen production from renewables: A review on the synergistic effect between anatase and rutile phases of TiO₂[J]. Mater. Renew. Sustain. Energy, 2012, 1(1): 3.

[19] You Y F, Xu C H, Xu S S, Cao S, Wang J P, Huang Y B, Shi S Q. Structural characterization and optical property of TiO₂ powders prepared by the sol-gel method[J]. Ceram. Int., 2014, 40(6): 8659-8666.

[20] Miszczak S, Pietrzyk B. Anatase-rutile transformation of TiO₂ sol-gel coatings deposited on different substrates[J]. Ceram. Int., 2015, 41(6): 7461-7465.

[21] Gao R Q(高如琴), Zhu L F(朱灵峰), Guo Y P(郭毅萍), Zhang R T(张润涛). Effect of heat treatment temperature on photocatalytic property of nano TiO₂ films[J]. J. Silicates (硅酸盐学报), 2011, 39(2): 325-328+333.

[22] Tang J, Meng H M, He Y F. Energy-saving synthesis of electrolytic manganese dioxide using oxygen cathode with Pt/TiO₂-CN_x nanocatalysts[J]. J. Appl. Electrochem., 2017, 47(5): 653-659.

[23] Tang J, Meng H M. TiO₂-modified CN_x nanowires as a Pt electrocatalyst support with high activity and durability for the oxygen reduction reaction[J]. Phy. Chem. Chem. Phys., 2016, 18(3): 1500-1506.

[24] Tang J, Meng H M, Li S, Yu M H, Li H, Shi J H. The energy saving mechanism of gas diffusion electrode based on Pt/C catalyst for saving energy and green electrodeposition of manganese dioxide[J]. Electrochim. Acta, 2015, 170: 92-97.

[25] Tang J, Meng H M, Liang X. Gas diffusion electrode with platinum/titanium nitride-carbon nitride nanocatalysts for the energy-saving and environment-friendly electrodeposition of manganese dioxide[J]. J. Clean. Prod., 2016, 137: 903-909.

[26] Ma X L(马旭莉), Yang Y Y(杨言言), Wang Z D(王忠德), Hao X G(郝晓刚). Determination of electroactive area of porous membrane electrode by electrodeposition of nickel ferricyanide[J]. Rare metal mater. Eng.(稀有金属材料与工程), 2013, 42(4): 776-780.

[27] Fan M Y(范梦阳), Qiao J L(乔锦丽). Study on high efficiency electrochemical reduction of CO₂ by CuO/Cu₂O nano catalyst with multistage structure[C]// Annual conference of Chinese Society of Environmental Sciences(中国环境科学学会学术年会), China, Sichuan, 2014: 5246-5256.

[28] Tzorbatzoglou F, Brouzgou A, Jing S Y, Wang Y, Song S Q, Tsiakaras P. Oxygen reduction and hydrogen oxidation reaction on novel carbon supported Pd_xIr_y electrocatalysts[J]. Int. J. Hydrogen Energ., 2018, 43(26): 11766-11777.

[29] Bakardjieva S, Šubrt J, Štengl V, Dianez M J, Sayagues M J. Photoactivity of anatase-rutile TiO₂ nanocrystalline mixtures obtained by heat treatment of homogeneously precipitated anatase[J]. Appl. Cataly. B-Environ., 2005, 58(3-4): 193-202.

[30] Lv K L, Yu J G, Deng K J, Li X H, Li M. Effect of phase structures on the formation rate of hydroxyl radicals on the surface of TiO₂[J]. J. Phy. Chem. Solids, 2010, 71(4): 519-522.

[31] Yan M C, Chen F, Zhang J L, Anpo M. Preparation of controllable crystalline titania and study on the photocatalytic properties[J]. J. Phys. Chem. B, 2005, 109(18): 8673-8678.

[32] Ma X, Xue L H, Li X B, Yang M, Yan Y W. Controlling the crystalline phase of TiO₂ powders obtained by the solution combustion method and their photocatalysis activity[J]. Ceram. Int. 2015, 41(9): 11927-11935.

[33] Catauro M, Tranquillo E, Poggetto G, Pasquali M, Dell’Era A, Ciprioti S V. Influence of the heat treatment on the particles size and on the crystalline phase of TiO₂ synthesized by the sol-gel method[J]. Mater., 2018, 11(12): 2364.

[34] Bakardjieva S, Šubrt J, Štengl V, Večerníková E, Bezdička P. Comparison of photocatalytical properties of anata-se and rutile TiO₂ in degradation of 4-Chlorophenol in aqueous solution[J]. Solid State Phenom., 2003, 90-91:7-12.

[35] Roen L M, Paik C H, Jarvic T D. Electrocatalytic corrosion of carbon support in PEMFC cathodes[J]. Electro-chem. Solid SL, 2004, 7(1): A19-A22.

[36] Ohno T, Tokieda K, Higashida S, Matsumura M. Synergism between rutile and anatase TiO₂ particles in photocatalytic oxidation of naphthalene[J]. Appl. Catal. A-Gen., 2003, 244(2): 383-391.