The one named for Crabtree is a significant improv
The one named for Crabtree is a significant improvement over one named for Wilkinson. Some of these are usually "poisoned" with lead compounds, and are usually deposited onto surfaces such as carbon or calcium carbonate, while another kind is made from titanium-aluminum complexes of organic compounds and is used in polymerization of 1-alkenes. Those examples are named for Lindlar and Ziegler-Natta. For 10 points, identify these entities which speed up chemical reactions without being consumed themselves.
The one named for Crabtree is a significant improvement over one named for Wilkinson.
{catalysts}