In-situ Loaded Pt-Co High Index Facets Catalysts: Preparation and Electrocatalytic Performance

doi:10.15541/jim20220298

Abstract

Abstract:

Direct ethanol fuel cell (DEFC) has been widely studied because of its advantages of easy fuel availability, green and high effiency. However, DEFC catalysts are still frustrated with low catalytic efficiency and poor catalyst stability, which restrict its rapid development. In this work, XC-72R carbon black-loaded Pt₁Co_x/C high-index crystalline nanocatalysts were prepared in one step by liquid-phase hydrothermal synthesis, using polyvinylpyrrolidone (PVP k-25) as dispersant and reducing agent, glycine as surface control agent and co-reducing agent, and modulating the molar ratio of Pt-Co metal precursors to achieve the in-situ growth of catalyst particles on carbon carriers. The exposed high index crystalline facets of the Pt₁Co_1/3/C nanocatalyst mainly consisted of (410), (510) and (610) crystalline facets. The growth pattern of the Pt₁Co_1/3/C nanocatalyst grains varied from 'sphere-like' to cubic, and eventually to concave with high index grain orientation. The Pt₁Co_1/3/C nanocatalyst with high index crystalline surface has the highest electrocatalytic activity with an electrochemically active surface area of 18.46 m²/g, a current density of 48.70 mA/cm² for the ethanol oxidation peak, a steady state current density of 8.29 mA/cm² and a potential of 0.610 V for the CO oxidation peak. This indicates that the defect atoms such as steps and kinks on the surface of the catalyst with high index crystal plane can increase the active sites, thus showing excellent electrocatalytic performance. This study may provide a theoretical basis for the development and industrial application of high index crystalline catalyst materials.

Key words: hydrothermal method, Pt-Co catalyst, high index crystal plane, in-situ growth, direct ethanol fuel cell

CLC Number:

TM911

YAO Yishuai, GUO Ruihua, AN Shengli, ZHANG Jieyu, CHOU Kuochih, ZHANG Guofang, HUANG Yarong, PAN Gaofei. In-situ Loaded Pt-Co High Index Facets Catalysts: Preparation and Electrocatalytic Performance[J]. Journal of Inorganic Materials, 2023, 38(1): 71-78.

Figures/Tables 9

Fig. 1 XRD patterns of catalysts

Fig. 2 Surface morphologies of Pt1Co1/3/C high-index crystalline nanocatalyst (a) TEM and (b) HRTEM images; (c) SAED image; (d-f) EDS surface sweep mapping images; (g-i) High-index crystalline atomic model for Pt1Co1/3/C high-index crystalline nanocatalysts; Colorful spheres in (g-i) represent different layers of atoms

Fig. S1 TEM, HRTEM images and histograms of particle size distributions for Pt1Cox/C high index crystalline nanocatalysts (a1-a3) Pt/C; (b1-b3) Pt1Co1/4/C; (c1-c3) Pt1Co1/3/C; (d1-d3) Pt1Co1/2/C; (e1-e3) Pt1Co1/C

Table 1 Pt1Cox/C high index crystalline surface catalyst depression angle vs. exposed crystal surface

Catalyst	Angle of depression/(°)	Exposure of crystalline surfaces
Pt/C	8.1, 6.5, 5.9, 10.2, 9.3, 7.8, 7.1, 7.4	(610), (710), (810)
Pt₁Co_1/4/C	9.7, 9.6, 8.4, 10.7, 11.8, 11.7, 11.9, 13.3	(410), (510), (610), (710)
Pt₁Co_1/3/C	14.4, 11.3, 10.6, 12.7, 10.1, 14.6, 11.9, 11.2	(410), (510), (610)
Pt₁Co_1/2/C	10.0, 14.7, 10.5, 13.9, 13.4, 12.1, 14.1, 14.0	(410), (510), (610)
Pt₁Co₁/C	9.4, 10.1, 9.6, 10.3, 7.3, 14.1, 14.2, 9.7	(410), (610), (810)

Fig. 3 Pt4f XPS spectra of (a) Pt/C and (b) Pt1Co1/3/C

Table 1 XPS fitting results for Pt/C and Pt1Co1/3/C catalysts

Catalyst	Pt(0)/eV	Relative ratio/%	Pt(II)/eV	Relative ratio/%
Pt/C	70.30,73.60	52.67	70.95,74.45	47.33
Pt₁Co_1/3/C	70.15,73.55	53.04	70.85,74.35	46.96

Fig. S2 TEM images and histograms of particle size distributions of Pt1Co1/3/C high index crystalline catalysts at different holding time (a1, a2) 1 h; (b1, b2) 3 h; (c1, c2) 5h; (d1, d2) 7 h; (e1, e2) 9 h; (f1, f2) 10 h

Fig. 4 Electrocatalytic performance of catalysts (a) H adsorption-desorption curves of the catalysts in 0.5 mol/L H2SO4 saturated with N2; (b) Cyclic voltammetric curves of the catalysts in 0.5 mol/L H2SO4+1 mol/L CH3CH2OH Colorful figures are available on website

Fig. 5 Stability and anti-poisoning performance of catalysts (a) Timing current curves of the catalysts in 0.5 mol/L H2SO4+1 mol/L CH3CH2OH; (b) CO dissolution curves of catalysts in 0.5 mol/L H2SO4 Colorful figures are available on website

References 36

[1]	LUO S P, SHEN P K. Concave platinum-copper octopod nanoframes bounded with multiple high-index facets for efficient electrooxidation catalysis. ACS Nano, 2017, 11(12): 11946. DOI PMID
[2]	XUE S F, DENG W T, YANG F, et al. Hexapod Pt RuCu nanocrystalline alloy for highly efficient and stablemethanol oxidation. ACS Catalysis, 2018, 8(8): 7578. DOI URL
[3]	TANG M, LUO S P, WANG K, et al. Simultaneous formation of trimetallic Pt-Ni-Cu excavated rhombicdodecahedrons with enhanced catalytic performance for the methanol oxidation reaction. Nano Research, 2018, 11(9): 4786. DOI URL
[4]	MA Y X, YIN L S, YANG T, et al. One-pot synthesis of concave platinum-cobalt nanocrystals and their superior catalytic performances for methanol electrochemical oxidation and oxygen electrochemical reduction. ACS Applied Materials & Interfaces, 2017, 9(41): 36164.
[5]	LUO M C, SUN Y J, QIN Y N, et al. Surface and near-surface engineering of PtCo nanowires at atomic scale for enhanced electrochemical sensing and catalysis. Chemistry of Materials, 2018, 30(19): 6660. DOI URL
[6]	ZHANG T, BAI Y, SUN Y Q, et al. Laser-irradiation induced synthesis of spongy AuAgPt alloy nanospheres with high-index facets, rich grain boundaries and subtle lattice distortion for enhanced electrocatalytic activity. Journal of Materials Chemistry A, 2018, 6(28): 13735. DOI URL
[7]	YANG P P, YUAN X L, HU H C, et al. Solvothermal synthesis of alloyed PtNi colloidal nanocrystal clusters (CNCs) with enhanced catalytic activity for methanol oxidation. Advanced Functional Materials, 2018, 28(1): 1704774. DOI URL
[8]	ZHU Y, GU J, YU T, et al. Synthesis and property of platinum- cobalt alloy nano catalyst. Journal of Inorganic Materials, 2021, 36(3): 299. DOI URL
[9]	ZHANG Z C, LIU G G, CUI X Y, et al. Crystal phase and architecture engineering of lotus-thalamus-shaped Pt-Ni anisotropic superstructures for highly efficient electrochemical hydrogen evolution. Advanced Materials, 2018, 30(30): e1801741.
[10]	LUO S P, TANG M, SHEN P K, et al. Atomic-scale preparation of octopod nanoframes with high-index facets as highly active and stable catalysts. Advanced Materials, 2017, 29(8): 01687.
[11]	LUO M C, SUN Y J, ZHANG X, et al. Stable high-index faceted Pt skin on zigzag-like Pt Fe nanowires enhances oxygen reduction catalysis. Advanced Materials, 2018, 30(10): 1705515. DOI URL
[12]	XIE S F, CHOI S, LU N, et al. Atomic layer-by-layer deposition of Pt on Pd nanocubes for catalysts with enhanced activity and durability toward oxygen reduction. Nano Letters, 2014, 14(6): 3570. DOI PMID
[13]	LUO Y, FENG J Z, FENG J, et al. Research progress on advanced carbon materials as Pt support for proton exchange membrane fuel cells. Journal of Inorganic Materials, 2020, 35(4): 407. DOI
[14]	ZHANG J, LANGILLE M, PERSONICK M L, et al. Concave cubic gold nanocrystals with high-index facets. Journal of the American Chemical Society, 2010, 132(40): 14012. DOI PMID
[15]	QIN Y C, ZHANG X, DAI X P, et al. Graphene oxide-assisted synthesis of Pt-Co alloy nanocrystals with high-index facets and enhanced electrocatalytic properties. Small, 2016, 12(4): 524. DOI PMID
[16]	TIAN N, XIAO J, ZHOU Z Y, et al. Pt-group bimetallic nanocrystals with high-index facets as high performance electrocatalysts. Faraday Discussions, 2013, 162: 77. PMID
[17]	ZHU C L, YIN Z X, LAI W H, et al. Fe-Ni-Mo nitride porous nanotubes for full water splitting and Zn-air batteries. Advanced Energy Materials, 2018, 8(36): 1802327.
[18]	OUYANG Y R, CAO H J, WU H J, et al. Tuning Pt-skinned PtAg nanotubes in nanoscales to efficiently modify electronic structure for boosting performance of methanol electrooxidation. Applied Catalysis B: Environmental, 2020, 265(C): 118606. DOI URL
[19]	QIN C L, FAN A X, ZHANG X, et al. The in situ etching assisted synthesis of Pt-Fe-Mn ternary alloys with high-index facets as efficient catalysts for electro-oxidation reactions. Nanoscale, 2019, 11(18): 9061. DOI URL
[20]	JOHANEK V, LAURINA M, GRANT A W, et al. Fluctuations and bistabilities on catalyst nanoparticles. Science, 2004, 304(5677): 1639. PMID
[21]	HONKALA K, HELLMAN A, REMEDIAKIS I N, et al. Ammonia synthesis from first-principles calculations. Science, 2005, 307(5709): 555. DOI PMID
[22]	SHAO M H, CHANG Q W, DODELET J P, et al. Recent advances in electrocatalysts for oxygen reduction reaction. Chemical Reviews, 2016, 116(6): 3594. DOI PMID
[23]	ZHANG Z C, HUI J F, LIU Y S, et al. Glycine-mediated syntheses of Pt concave nanocubes with high-index {hk0} facets and their enhanced electrocatalytic activities. Langmuir, 2012, 28(42): 148458.
[24]	GUO S J, DONG S J, WANG E K. Three-dimensional Pt-on-Pd bimetallic nanodendrites supported on graphene nanosheet: facile synthesis and used as an advanced nanoelectrocatalyst for methanol oxidation. ACS Nano, 2010, 4(1): 547. DOI PMID
[25]	PARK K W, CHOI J H, SUNG Y E, et al. Structural, chemical, and electronic properties of Pt/Ni thin film electrodes for methanol electrooxidation. The Journal of Physical Chemistry B, 2003, 107(24): 5851. DOI URL
[26]	YU X F, WANG D S, PENG Q, et al. High performance electrocatalyst: Pt-Cu hollow nanocrystals. Chemical Communications, 2011, 47(28): 8094. DOI URL
[27]	WANG Y, ZHUO H Y, ZHANG X, et al. Synergistic effect between undercoordinated platinum atoms and defective nickel hydroxide on enhanced hydrogen evolution reaction in alkaline solution. Nano Energy, 2018, 48: 590. DOI URL
[28]	GUO R H, QIAN F, AN S L, et al. Effect of acid treatment on electrocatalytic performance of PtNi catalyst. Chemical Research in Chinese Universities, 2020, 37(3): 686. DOI URL
[29]	ZHU T W, HENSEN E J M, SANTEN R A, et al. Roughening of Pt nanoparticles induced by surface-oxide formation. Physical Chemistry Chemical Physics, 2013, 15(7): 2268. DOI PMID
[30]	YU T, KIM D Y, ZHANG H, et al. Platinum concave nanocubes with high-index facets and their enhanced activity for oxygen reduction reaction. Angewandte Chemie International Edition, 2011, 123(12): 2825.
[31]	HUANG M H, JIANG Y Y, JIN C H, et al. Pt-Cu alloy with high density of surface Pt defects for efficient catalysis of breaking C-C bond in ethanol. Electrochimica Acta, 2014, 125: 29. DOI URL
[32]	SHI Y, MA Z R, XIAO Y Y, et al. Electronic metal-support interaction modulates single-atom platinum catalysis for hydrogen evolution reaction. Nature Communications, 2021, 12(1): 3021. DOI PMID
[33]	WEI Z Z, YAO Z H, ZHOU Q, et al. Optimizing alkyne hydrogenation performance of Pd on carbon in situ decorated with oxygen-deficient TiO₂ by integrating the reaction and diffusion. ACS Catalysis, 2019, 9(12): 10656. DOI URL
[34]	CHEN W L, GAO W P, TU P, et al. Neighboring Pt atom sites in ultrathin FePt nanosheet for efficient and highly CO-tolerant oxygen reduction reaction. Nano Letters, 2018, 18(9): 5905. DOI URL
[35]	LIAN X, GUO W L, LIU F L, et al. DFT studies on Pt₃M (M=Pt, Ni, Mo, Ru, Pd, Rh) clusters for CO oxidation. Computational Materials Science, 2015, 96: 237. DOI URL
[36]	ZHU Y M, BU L Z, SHAO Q, et al. Structurally ordered Pt₃Sn nanofibers with highlighted antipoisoning property as efficient ethanol oxidation electrocatalysts. ACS Catalysis, 2020, 10(5): 3455. DOI URL