Synthesis of VTMS(X)-HMS-3 mesoporous ordered silica for hydrogen storage

• VTMS-modified hexagonal mesoporous silica has been synthesized via co-condensation.
• The effect of increasing VTMS loading on hydrogen storage capacity was determined.
• Hydrogen adsorption capacity increased with increasing VTMS (0% ≤ X ≤ 31.5%).
• VTMS(31.5)-HMS-3 surpasses the capacity of unmodified HMS-3 at 77.3 K and 825 mmHg.

Vinyl trimethoxysilane (VTMS)-modified hexagonal mesoporous silica (HMS-3) has been synthesized at varied loading concentrations of VTMS to determine the effect of VTMS loading on hydrogen adsorption capacity. Materials were synthesized with 0, 10, 20, and 31.5 mol percent starting VTMS with respect to total silica precursor. In the modified VTMS(X)-HMS-3 silica submicron particles (X = 0%, 10%, 20%, and 31.5%), hydrogen adsorption capacity increased with a maximum of 0.72 wt% adsorbed by VTMS(31.5)-HMS-3 at 77.3 K and 825 mmHg. This adsorption surpass the adsorption capacity of the unmodified VTMS(0)-HMS-3, which attained 0.50 wt% adsorption at the same temperature and pressure. The correlative increasing trend in adsorption capacity following increased organic modification provides inspiration for similar modifications to periodic mesoporous organosilicas (PMO), which exhibit higher adsorption capacity than traditionally modified particles.

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