Effects of Pressure on the Chemical Properties of the Solid Surface. II. The Surface Acidity and the Catalytic Activity of Compressed Potassium Bisulfate

Abstract

Abstract Experimental studies of the chemical properties of the surface of potassium bisulfate samples which had been subjected to compressions of 0–3750 kg./cm2 at room temperature were carried out. Namely, on the compressed sample, the surface acidity at room temperature was measured by the indicator method, while the catalytic activity for the conversion of acetaldehyde to metaldehyde was measured at the temperature of a dry ice-methanol mixture by the bulk polymerization technique. Experimental results showed that the compression of the bisulfate resulted in an increase in the surface acidity at H0=1.5 and in a reduction of the acidity at H0=4.0. Further, it was found that the increase in the compressing pressure resulted in an increase in the catalytic activity of the sample. Thus, the existence of a close relation between the catalytic activity and the surface acidity at H0=1.5, and the effectiveness of the pressure in the improvement of the catalytic activity through changing the acid strength distribution on the sample surface were experimentally demonstrated.