Enhanced Hydrogen Adsorption on Hydrochloric Acid–Activated Cu–BDC Metal Organic Framework: Structural and Performance Analysis

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ABSTRACT

This study investigates the activation, characterization, and hydrogen adsorption properties of pristine and hydrochloric acid-activated Cu-BDC metal-organic frameworks (MOFs). The activation process aimed to enhance the surface area and pore volume, thereby improving hydrogen storage capabilities. Structural and morphological analyses were conducted using various techniques. X-ray diffraction (XRD) revealed a highly crystalline, well-organized framework, with additional peaks in the activated sample indicating phase transitions induced by activation. Fourier-transform infrared (FT-IR) spectroscopy confirmed the presence of functional groups, including -COO and C-H vibrations of aromatic rings, signifying the retention of essential framework components. Scanning electron microscopy (SEM) showcased regular, cubic microcrystals with homogeneously distributed particles. Thermal stability was assessed via thermogravimetric analysis (TGA), demonstrating that the material is thermally robust. Hydrogen adsorption measurements were performed at 300 K, 126 K, and pressures of 8 and 10 bar. The pristine Cu-BDC MOF exhibited a hydrogen uptake of 0.88 wt% at 126 K and 10 bar, which improved to 1.12 wt% upon activation. The enhanced uptake in the activated sample is attributed to the increased surface area and pore volume, providing more adsorption sites for hydrogen molecules. Notably, low-temperature and high-pressure conditions were found to significantly enhance hydrogen storage performance. These findings highlight the potential of functionalized Cu-BDC MOFs as promising candidates for hydrogen storage applications, contributing to advancements in sustainable energy storage technologies. The study aligns with global efforts to meet the DOE targets for efficient hydrogen storage systems.

Significance of the Study:

The study highlights the role of material activation in improving hydrogen storage efficiency, a crucial aspect of clean energy technology. By increasing surface area and adsorption sites, hydrochloric acid activation enhances hydrogen uptake, making Cu-BDC MOFs viable for practical applications. The research aligns with global efforts to develop efficient hydrogen storage systems, supporting the transition to renewable energy.

Summary of the Study:

This study explores the enhancement of hydrogen storage in Cu-BDC metal-organic frameworks (MOFs) through hydrochloric acid activation. The activation process improves surface area and pore volume, increasing adsorption sites for hydrogen molecules. Structural and morphological characterizations confirm crystallinity, functional group retention, and thermal stability. Hydrogen adsorption experiments reveal that activation enhances storage capacity from 0.88 wt% to 1.12 wt% at 126 K and 10 bar. The findings demonstrate the potential of activated Cu-BDC MOFs in advancing hydrogen storage technologies, contributing to sustainable energy solutions.