Rapid hydrothermal synthesis of bimetal cobalt nickel phosphate molecular sieve CoVSB-1 and its ammonia gas adsorption property

Bimetal cobalt nickel phosphate CoVSB-1 molecular sieves with the yield of about 88 wt% have been synthesized rapidly in 4 h at 443 K under hydrothermal conditions. About 32.3 and 23.7 wt% of ammonia gases can be adsorbed by VSB-1 and CoVSB-1, respectively, after being activated for 20 min at 373 K. Compared with the related adsorption amount of 17.5 wt% for zeolite NaA, their adsorption amounts are very high, which may be due to the large pore diameters of 0.9 nm, high surface areas (ca. 134 and 156 m2/g for VSB-1 and CoVSB-1, respectively), suitable P-OH acidic activities, and a large amount of frameworks transition-metal nickels and/or cobalt coordination centers. The possible chemisorption mechanism could be deduced through the XRD patterns, FT-IR and UV-Vis spectra analytic results.