Kummamuru Nithin B, Ciocarlan Radu-George, Houlleberghs Maarten, Martens Johan, Breynaert Eric, Verbruggen Sammy W, Cool Pegie, Perreault Patrice
Sustainable Energy Air & Water Technology (DuEL), Department of Bioscience Engineering, University of Antwerp Groenenborgerlaan 171 2020 Antwerpen Belgium.
Laboratory for the Electrification of Chemical Processes and Hydrogen (ElectrifHy), University of Antwerp Olieweg 97 2020 Antwerp Belgium
Sustain Energy Fuels. 2024 Apr 15;8(13):2824-2838. doi: 10.1039/d4se00114a. eCollection 2024 Jun 25.
This study introduces solid-state tuning of a mesostructured cellular foam (MCF) to enhance hydrogen (H) storage in clathrate hydrates. Grafting of promoter-like molecules (, tetrahydrofuran) at the internal surface of the MCF resulted in a substantial improvement in the kinetics of formation of binary H-THF clathrate hydrate. Identification of the confined hydrate as sII clathrate hydrate and enclathration of H in its small cages was performed using XRD and high-pressure H NMR spectroscopy respectively. Experimental findings show that modified MCF materials exhibit a ∼1.3 times higher H storage capacity as compared to non-modified MCF under the same conditions (7 MPa, 265 K, 100% pore volume saturation with a 5.56 mol% THF solution). The enhancement in H storage is attributed to the hydrophobicity originating from grafting organic molecules onto pristine MCF, thereby influencing water interactions and fostering an environment conducive to H enclathration. Gas uptake curves indicate an optimal tuning point for higher H storage, favoring a lower density of carbon per nm. Furthermore, a direct correlation emerges between higher driving forces and increased H storage capacity, culminating at 0.52 wt% (46.77 mmoles of H per mole of HO and 39.78% water-to-hydrate conversions) at 262 K for the modified MCF material with fewer carbons per nm. Notably, the substantial H storage capacity achieved without energy-intensive processes underscores solid-state tuning's potential for H storage in the synthesized hydrates. This study evaluated two distinct kinetic models to describe hydrate growth in MCF. The multistage kinetic model showed better predictive capabilities for experimental data and maintained a low average absolute deviation. This research provides valuable insights into augmenting H storage capabilities and holds promising implications for future advancements.
本研究介绍了对介孔蜂窝泡沫（MCF）进行固态调谐以增强笼形水合物中的氢（H）存储。在MCF的内表面接枝类促进剂分子（如四氢呋喃），使得二元H-THF笼形水合物的形成动力学有了显著改善。分别使用XRD和高压H NMR光谱确定受限水合物为sII笼形水合物，并确定H在其小笼中的包合情况。实验结果表明，在相同条件下（7 MPa、265 K、用5.56 mol% THF溶液使孔隙体积达到100%饱和），改性MCF材料的H存储容量比未改性的MCF高约1.3倍。H存储的增强归因于将有机分子接枝到原始MCF上产生的疏水性，从而影响水的相互作用并营造有利于H包合的环境。气体吸收曲线表明存在一个实现更高H存储的最佳调谐点，有利于每纳米更低的碳密度。此外，更高的驱动力与增加的H存储容量之间存在直接关联，对于每纳米碳原子数较少的改性MCF材料，在262 K时最终达到0.52 wt%（每摩尔H₂O含46.77毫摩尔H，水与水合物的转化率为３９.７８%）。值得注意的是，在无需耗能过程的情况下实现的大量H存储容量突出了固态调谐在合成水合物中进行H存储的潜力。本研究评估了两种不同的动力学模型来描述MCF中水合物的生长。多阶段动力学模型对实验数据显示出更好的预测能力，并且平均绝对偏差较低。这项研究为提高H存储能力提供了有价值的见解，并对未来的进展具有广阔的前景。
