COPPER(I) CHLORIDE-ETHANEDIAMINE COMPLEX SUPPORTED ON SILICA-GEL AS ADSORBENT FOR CARBON-MONOXIDE

A copper(I) chloride-N,N,N',N'-tetramethyl-1,2-ethanediamine complex s upported on silica gel was prepared by mixing porous silica gel with a n acetonitrile solution containing the complex composed of copper(I) c hloride (CuCl) and N,N,N',N'-tetramethyl-1,2-ethanediamine (M4en) unde r nitrogen, followed by removal of liquid phase under reduced pressure . The resulting silica gel, 6.0 g, supported 4.92 mmol of 1:1 CuCl-M4e n complex. It rapidly adsorbed carbon monoxide (CO) at 30 degrees C un der 1.0 atm of CO, and the equilibrium amount of adsorbed CO was 4.30 mmol (87 mol% against supported complex). The adsorbed CO was rapidly desorbed by maintaining it at 120 degrees C under 1.0 atm or at 30 deg rees C under 0.1 mmHg. The adsorption-desorption cycle was repeated wi thout any deterioration. The equilibrium amount of adsorbed CO (4.30 m mol) was 11.8 times that of adsorbed carbon dioxide (0.37 mmol), and 4 0.9 times that of adsorbed methane (0.11 mmol) at 30 degrees C under 1 .0 atm. The reversible and selective adsorption of CO was attributed t o formation of 1:1:1 CuCl-M4en-CO complex. When the adsorbent contacte d with oxygen, the CO-adsorbing ability decreased. The adsorbing abili ty was completely recovered by maintaining the adsorbent at 120 degree s C under 1.0 atm of CO for 3 h. (C) 1998 Elsevier Science B.V. All ri ghts reserved.