Glycerine is known as a negative catalyst. why?

The presence of 1-2% ethanol as catalyst, suppresses the oxidation of chloroform with oxygen to give a poisonous gas called phosgene. ... Here glycerol acts as negative catalyst. Criteria or characteristics of catalysts. i. The mass and chemical composition of catalyst should remain unchanged at the end of the reaction.

Explanation:

a. energy is absorbed in the reaction.

if in a given reaction the energy of products is greater than the energy of reactants it means that reaction is endothermic and during the reaction, the energy is absorbed by reactants. in an endothermic reaction, the products have more stored chemical energy than the reactants. and in this reaction the reactants are more stable than products before the compounds with less energy are always more stable.