CBSE Class 12-science Answered

A number of criteria are required to be met before a metal can be selected as a 'good' catalyst for any reaction. The three most important are:
(i) its activity, that is the speed with which it makes the reaction go,
(ii) its selectivity, that is, the extent to which it produces the desired product rather than any others, and
(iii) its active life, that is, how long it can be used before it becomes deactivated by poisons, or loses its mechanical stability.