直接甲醇燃料电池(DMFC)的成功商业化受到甲醇氧化活性和阳极催化剂寿命不足的阻碍。在DMFC的广泛使用中,高效且成本有效的电极材料是必要的。虽然铂(Pt)仍然是阳极甲醇氧化反应(MOR)电催化剂的主要成分,由于一氧化碳(CO)中毒,其在DMFC系统中的单独使用受到限制,不稳定性,甲醇交叉,和高成本。这些限制阻碍了Pt作为电催化剂的经济可行性。在这里,我们介绍了粉末活性炭(PAC)和颗粒活性炭(GAC)的用途,两者均来自澳洲坚果壳(MNS),一种生物质。这些生物基碳材料被整合到具有还原氧化石墨烯(rGO)的混合载体中,旨在提高Pt电催化剂的性能并降低生产成本。合成催化剂的电化学和物理化学表征,进行Pt-rGO/PAC-1:1、Pt-rGO/PAC-1:2、Pt-rGO/GAC-1:1和Pt-rGO/GAC-1:2。X射线衍射分析显示微晶尺寸为1.18nm至1.68nm。平均粒径为1.91nm至2.72nm的高分辨率透射电子显微镜(HRTEM)图像显示了Pt纳米颗粒的球形分散体,在所有催化剂上都有一些团聚。测定电化学活性表面积(ECSA),其中Pt-rGO/GAC-1:1表现出73.53m2g-1的最高ECSA。尽管ECSA很高,Pt-rGO/GAC-1:1显示出最低的甲醇氧化反应(MOR)电流密度,表示催化效率差的活性位点。Pt-rGO/PAC-1:1和Pt-rGO/PAC-1:2表现出最高的MOR电流密度,分别为0.77mA*cm-2和0.74mA*cm-2。此外,Pt-rGO/PAC-1:2和Pt-rGO/PAC-1:1表现出优异的电催化质量(比)活性,分别为7.55mA/mg(0.025mA*cm-2)和7.25mA/mg(0.021mA*cm-2),分别。计时电流法测试显示Pt-rGO/PAC-1:2和Pt-rGO/PAC-1:1是最稳定的催化剂。此外,它们在耐久性测试后表现出最低的电荷转移电阻和最高的MOR电流密度,突出了它们在DMFC应用中的潜力。合成的Pt负载在PAC杂化物上表现出显著的催化性能,稳定性,和CO耐受性,强调其提高DMFC效率的潜力。
The successful commercialization of direct methanol fuel cells (DMFCs) is hindered by inadequate methanol oxidation activity and anode catalyst longevity. Efficient and cost-effective electrode materials are imperative in the widespread use of DMFCs. While Platinum (Pt) remains the primary component of anodic methanol oxidation reaction (MOR) electrocatalysts, its utilization alone in DMFC systems is limited due to carbon monoxide (CO) poisoning, instability, methanol crossover, and high cost. These limitations impede the economic feasibility of Pt as an electrocatalyst. Herein, we present the use of powdered activated carbon (PAC) and granular activated carbon (GAC), both sourced from macadamia nut shells (MNS), a type of biomass. These bio-based carbon materials are integrated into hybrid supports with reduced graphene oxide (rGO), aiming to enhance the performance and reduce the production cost of the Pt electrocatalyst. Electrochemical and physicochemical characterizations of the synthesized catalysts, including Pt-rGO/PAC-1:1, Pt-rGO/PAC-1:2, Pt-rGO/GAC-1:1, and Pt-rGO/GAC-1:2, were conducted. X-ray diffraction analysis revealed crystallite sizes ranging from 1.18 nm to 1.68 nm. High-resolution transmission electron microscopy (HRTEM) images with average particle sizes ranging from 1.91 nm to 2.72 nm demonstrated spherical dispersion of Pt nanoparticles with some agglomeration across all catalysts. The electrochemical active surface area (ECSA) was determined, with Pt-rGO/GAC-1:1 exhibiting the highest ECSA of 73.53 m2 g-1. Despite its high ECSA, Pt-rGO/GAC-1:1 displayed the lowest methanol oxidation reaction (MOR) current density, indicating active sites with poor catalytic efficiency. Pt-rGO/PAC-1:1 and Pt-rGO/PAC-1:2 exhibited the highest MOR current densities of 0.77 mA*cm-2 and 0.74 mA*cm-2, respectively. Moreover, Pt-rGO/PAC-1:2 and Pt-rGO/PAC-1:1 demonstrated superior electrocatalytic mass (specific) activities of 7.55 mA/mg (0.025 mA*cm-2) and 7.25 mA/mg (0.021 mA*cm-2), respectively. Chronoamperometry tests revealed Pt-rGO/PAC-1:2 and Pt-rGO/PAC-1:1 as the most stable catalysts. Additionally, they exhibited the lowest charge transfer resistances and highest MOR current densities after durability tests, highlighting their potential for DMFC applications. The synthesized Pt supported on PACs hybrids demonstrated remarkable catalytic performance, stability, and CO tolerance, highlighting their potential for enhancing DMFC efficiency.