Effect of sulfur on surface properties of complex carbon–silica adsorbents

Two series of carbon/silica (carbosil, CS) adsorbents were prepared on the basis of silica gel as a matrix and glucose as a carbon precursor by pyrolysis of 0.01, 0.03, 0.05 mol of glucose per 10 g of mesoporous silica gel Si-100. Initial samples (CSn) were modified with hydrogen sulfide (CSn/S). On preparation of the CSn series, only nitrogen (100 cm3/min) was used as a carrier gas. The CSn/S samples were prepared in the nitrogen (90 cm3/min) and hydrogen sulfide (60 cm3/min) atmosphere. Carbosils were studied using adsorption (nitrogen, butane, ammonia, and Ni(II)) and thermal analysis methods. During glucose pyrolysis in the hydrogen sulfide atmosphere the chemical reactions between glucose and hydrogen sulfide take place that leads to a greater yield of carbon deposits. The presence of sulfur on the carbosil surface has a negative effect on butane adsorption and the opposite effect is observed on the adsorption of ammonium and Ni(II).