Enhancing Hydrogen Adsorption Capacity of Metal Organic Frameworks M(BDC)TED_0.5 through Constructing a Bimetallic Structure

Abstract

Metal organic frameworks (MOFs) have promising application prospects in the field of hydrogen storage. However, the successful application of MOFs in the field is still limited by their hydrogen storage capacity. Herein, a series of M x M 1– x ( BDC )TED 0.5 (M = Zn, Cu, Co, or Ni) with a bimetallic structure was constructed by introducing two metal ions in the synthesis process. The results of X-ray diffraction, scanning electron microscopy, energy-dispersive spectroscopy, X-ray photoelectron spectroscopy, and inductively coupled plasma showed that the bimetallic structure with different content ratios can be stably constructed by a hydrothermal method. Among them, the Cu-based bimetal MOFs Cu 0.625 Ni 0.375 (BDC)TED 0.5 exhibited the best hydrogen storage capacity of 2.04 wt% at 77 K and 1 bar, which was 22% higher than that of monometallic Ni( BDC )TED 0.5 . The enhanced hydrogen storage capacity can be attributed to the improved specific surface area and micropore volume of bimetal MOFs by introducing an appropriate amount of bimetallic atoms.