Improvement of production efficiency of spray-synthesized HKUST-1

Spray synthesis of metal-organic frameworks (MOFs) is desirable for scaled production. In this study, we designed a new apparatus for spray-synthesizing MOFs, wherein an upward spraying and swirling air flow was applied to prevent loss of the precursor solution. We evaluated the effects of the flow rate and temperature of swirling air, temperature of the reactor tube, initial feed rate of the precursor solution, and precursor concentration on the yield, purity, space-time yield (STY), BET surface area, and average particle size. The swirling air flow along with re-spraying of the solution accumulated on the upward spray nozzle improved yield significantly. The highest STY was 45.7 kg/m(3)/day obtained at a precursor feed rate of 5 mL/min; the highest surface area was 1,872 m(2)/g obtained at a precursor concentration of 1.38 mol/L. The sample with the highest surface area exhibited 2.60 wt% of hydrogen adsorption capacity at 77 K and 1 bar, with 7.6-6.1 kJ/mol of heat of hydrogen adsorption. (C) 2021 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.

Automated summary

A new apparatus was designed for spray synthesis of metal-organic frameworks, significantly improving yield by optimizing the air flow and precursor solution conditions. Under the optimal conditions, the highest space-time yield was 45.7 kg/m(3)/day, the highest surface area was 1,872 m(2)/g, and the sample exhibited good hydrogen adsorption capacity.