Influence of surface modification by nitric acid on the dispersion of copper nitrate in activated carbon

High degree dispersion of catalyst in activated carbon plays an essential role in the cases of either activated carbon being a catalyst carrier or the catalytic preparation of activated carbon itself. The effect of surface modification by HNO3 on the dispersion of Cu(NO3)2 in coalbased activated carbon was investigated by Energy Diffraction Xray (EDX) and Scanning Electron Microscopy (SEM) techniques. Besides, activated carbons were prepared by reactivation of a commercial activated carbon loaded with Cu(NO3)2 after HNO3 modification. Results showed that treatment by HNO3 results in the rapid fall of adsorption capacity of the resulting activated carbon, and the greater the intensity of treatment, the more the decrease of adsorption capacity. However, washing of HNO3treated activated carbon has the effect of restoring the adsorption capacity of activated carbon. Apart from this, oxidation of activated carbon by nitric acid leads to the increase of oxygen functional groups on carbon surface, results in the uniform distribution of catalyst (copper nitrate) on both the interior and exterior surfaces of the activated carbon, produces an enhancement of catalyst dispersion, and improves the antisintering ability of the catalyst particulates. As a result, the catalytic ability of copper nitrate on the carbonsteam reaction is enhanced when activated carbon modified by HNO3 is used as a precursor for the preparation of advanced activated carbon by a second activation.