What catalyst is used for hydrogenation reactions?

Raney nickel – I’ve never used it myself; it’s said to be quite dangerous and flammable, haha. Operate with care

Nickel powder can be produced from aluminum-nickel alloys, and NaH should also work for this purpose; however, it is necessary to choose a catalyst that yields the highest yield, provides the best reaction results, and generates the fewest side reactions. Nickel catalysts, palladium on carbon, and NaH are all flammable catalysts; it is essential to prevent them from coming into contact with air during the reaction as well as during the post-reaction processing, otherwise there is a risk of fire.

The most common ones are Raney nickel and palladium on carbon

There’s also skeleton nickel! ! ! ! ! ! ! ! !

Zhongsi seems to use NiO, with a Si:NiO ratio of 50:1

This post was last edited by lgm5201318 on 2010-9-14 at 11:36. It depends on your reaction to determine whether it’s a carbonyl group, a benzene ring, or a double bond; different catalysts are suitable for different types of functional groups. For example, precious metal catalysts work well for benzene rings but are less effective for carbonyl groups. Additionally, I am also not very inclined toward chemical reduction; it is not cost-effective on an industrial scale. At the same time, it also depends on the process route you use. Taking *** reduction as an example, for reaction vessels, platinum carbon or Raney nickel can be used; for fixed-bed systems, copper loaded on silica gel can be employed as a catalyst ； Additionally, it is necessary to consider that different catalysts and reaction conditions are required depending on whether the phase is gas or liquid.

Nickel catalysts and palladium on carbon are commonly used in catalytic hydrogenation reactions; care must be taken during preparation and post-treatment! But there’s no need to be too nervous. Be careful: prevent spontaneous combustion during drying, and avoid poisoning during preparation. Be careful of changes in hydrogen pressure during use!

Palladium on carbon is more commonly used; the price of Raney nickel is relatively high

Palladium on carbon and Raney nickel each have their advantages and disadvantages. Raney nickel has a high density, settles quickly, is easy to separate, and allows for fast processing; reaction vessels can be used to increase production significantly ； The palladium-carbon filtration system is relatively complex; I’ve heard that filters using precious metal catalysts are made from sintered metals, and it seems that China does not possess advanced technology in this area, so imports are necessary.

Raney nickel is too dangerous; it produces sparks when exposed to air. Palladium carbon isn’t expensive either – with proper treatment, 90% of it can be activated again, and even with less effective treatment, over 70% can still be activated. The cost isn’t that high after all. Considering safety and other factors, palladium carbon is the better choice.