Carbon materials as catalysts for methylamines synthesis

This paper deals with the use of carbon materials as catalysts for methylamines synthesis. The reaction has been studied at atmospheric pressure and in the range 673-733 K. The behaviour of the catalysts is related to the textural and chemical surface characteristics of these materials. The samples with open porosity allow the reactives to access the acid chemical groups and they have the highest activities for the production of methylamines. Nevertheless, the samples with narrow porosity do not permit the access and they have very low activities. The reaction seems to follow a Langmuir-Hinshelwood (LH) process which proceeds via adsorption of ammonia and methanol on acid adjacent sites. It is shown that an important aspect of the process is the desorption of the reaction products which is assisted by ammonia in the gas phase. (C) 2002 Elsevier Science B.V. All rights reserved.