Talk:Raney nickel

Aluminium content
What is the usual aluminium content of Raney nickel? Might it be better to discribe it as finely divided nickel, rather than nickel-aluminium alloy? Physchim62 08:59, 22 October 2005 (UTC)


 * Off the top of my head I can tell you that the final Al content using a 50/50 starting alloy is usually between 10 to 20%. Of this percentage Al is present mostly in the nickel aluminide phase (NiAl), but depending on activation conditions more or less Al is leached from the other phases. I don't think describing it as a nickel-only catalyst is accurate, but describing it as mostly-Ni would be ;-) -- Rune Welsh | &tau;&alpha;&lambda;&kappa; | Esperanza  09:22, 22 October 2005 (UTC)


 * I was able to check my references just now, the average Ni content in commercial samples derived from a 50/50 starting alloy is 85%. So there you go. -- Rune Welsh | &tau;&alpha;&lambda;&kappa; | Esperanza  15:27, 22 October 2005 (UTC)


 * Are these percentages by mass or by molar fraction? The atomic mass of nickel is twice that of aluminium... Physchim62 19:31, 27 October 2005 (UTC)


 * Somehow I didn't see this comment before. Percentages are given by mass (% wt). -- Rune Welsh | &tau;&alpha;&lambda;&kappa; | Esperanza  16:09, 30 November 2005 (UTC)
 * The active catalyst is actually Ni5Al per Aldricimica Acta article. 75.253.119.222 (talk) 01:21, 6 July 2024 (UTC)

Teratogenicity of nickel
The article states that nickel metal is a known teratogen: do we have any references for that? It might also be better to describe it as a suspected carcinogen, given its IARC classification... although if you ingest it, it will transform into Class 1 nickel chloride in the stomach... Physchim62 08:59, 22 October 2005 (UTC)


 * The source is in the linked MSDS in the reference section: -- Rune Welsh | &tau;&alpha;&lambda;&kappa; |  Esperanza  09:22, 22 October 2005 (UTC)

Human females show allergic reactions to Nickel and even to Nickel in Stainless Steel (earing posts). Nickel metal not the culprit but soluble Nickel salts. Some vitamin supplements contain Nickel as a trace mineral requirement. TaylorLeem (talk) 21:38, 31 August 2020 (UTC)

Aminolysis of alcohols ?
The third sentence under the "Applications" section states:
 * It [Raney nickel] "has also found use in the alkylation of amines and the aminolysis of alcohols."

Can someone explain what aminolysis of alcohols is? Maybe provide a general chemical reaction using R groups or, otherwise, an example of a specific chemical reaction? It seems to me that aminolysis would be the cleavage or splitting of an amine, but an alcohol is typically not an amine. H Padleckas 07:02, 26 October 2005 (UTC)


 * Sorry, you're right. It's amination of alcohols, the exact opposite. -- Rune Welsh | &tau;&alpha;&lambda;&kappa; | Esperanza  10:30, 27 October 2005 (UTC)
 * OK, thank you. Now it makes sense.  H Padleckas 03:32, 28 October 2005 (UTC)

Factual inaccuracy in lead
In a materials science context, an amorphous solid is noncrystalline; however, according to the article, Raney nickel is composed of fine crystals ("fine grains" and "crystallite sizes" both imply this). This should be corrected. - Bantman 19:32, 13 December 2005 (UTC)


 * Very true. Fixed. -- Rune Welsh | &tau;&alpha;&lambda;&kappa; | Esperanza  13:27, 25 December 2005 (UTC)

Removed statements in the Applications section
I removed two statements in the Applications section.


 * Raney nickel is frequently used for organic syntheses in the laboratory, where it is often used as a practical alternative to aqueous reducing agents, such as sodium borohydride, in most of the reactions outlined above.

-and-


 * Thus the use of Raney nickel in this reaction may be used as a convenient alternative...

The reason is that Raney nickel is NOT the practical alternative to anything. Because of it's extreme pyrophoricity, Raney nickel is dangerous to handle in most laboratories. In my experience, Raney nickel has been the last alternative, and is only used when other options are impractical or don't work.

Don't get me wrong. I've used Raney nickel many times, but to say that it's a practical and convenient alternative is just wrong. ~K 19:33, 29 January 2006 (UTC)


 * I disagree. Reductive amination is a good example where Raney nickel and Pd/black are used instead of NaBH4 and related compounds. Also, Raney nickel is almost always stored in water so direct exposure to water is a non-issue. Replacing water with another solvent is pretty much trivial with the use of a manifold. -- Run e Welsh | &tau;&alpha;&lambda;&kappa; 19:59, 29 January 2006 (UTC)


 * You are correct. Reductive amination works very well with Pd-on-carbon and with sodium cyanoborohydride.  Both of these reagents give high yields comparable with RaNi.  Therefore, since both of these reagents are easy to handle and not pyrophoric, why not use them before trying RaNi.  Remember, I'm not dissuading usage of RaNi, but rather, not suggesting it is better than other alternatives.


 * Regarding the water, I don't understand the problem. (I think I either miswrote something or you misread something.)


 * Finally, I apologize for offending you about editting first and explaining later. It was not my intention to offend.  My only excuse is I was "Being Bold".  I find this method the best way of getting things done quickly. If you feel, this method is wrong and there's a better way to go about it, please tell me. ~K 20:43, 29 January 2006 (UTC)


 * You mentioned that pyrophoricity is an issue when handling RaNi in the lab. I tried to say that it isn't because it's sold in a slurry and handling under inert atmosphere in a manifold is simple, so there's little risk of exposure. Also, while its true Pd/black is used as an alternative to RaNi when yields are comparable, the removed text mentioned clearly that RaNi is an alternative to aqueous reducing agents. The problem with those is usually the separation of the aqueous phase and the formation of potentially toxic byproducts. Case in point, the frequent use (until recently) of NaBH3CN in reductive amination.


 * I have nothing against people being bold, but please consider that when the article is under a greater attention than usual (as is the case during an FAC nomination) it would be preferable to discuss things first. -- Run e Welsh | &tau;&alpha;&lambda;&kappa; 20:57, 29 January 2006 (UTC)

aluminium dissolved?
dissolves most of the aluminium out of the alloy.

I was under the impression that 2NaOH + Al -> H2 + Na2AlO2 (sodium aluminate) as covered in the reaction section. You can try this at home with some draino and alfoil: put the alfoil in a glass jar with a hole in the top, add a few flakes of draino and a little water, put the lid resting on the top, wait short while then light the hole with a taper. The lid will go up in the air with a nice bang.

This isn't really dissolving, but instead a chemical reaction. (I guess people tend to be a bit causal with dissolve - 'acid dissolves metal') njh 10:16, 21 February 2006 (UTC)


 * Most of the sources I consulted tend to refer to the leaching process as "dissolving" at some point during the discussion. This is probably because the excess NaOH prevents the precipitation of sodium aluminate so it remains effectively "dissolved" in solution. -- Run e Welsh | &tau;&alpha;&lambda;&kappa; 11:09, 15 August 2006 (UTC)

FA concerns
I have found at least one fact in the article, as well as some unsourced "however"s scattered about. Also, there is an external link in the intro, which I believe is a no-no. Furthermore, the last paragraph of "Properties" is unsourced. If this is going to stay FA, it will need much more work; I'd take it to FAR if I hadn't recently listed one. Ten Pound Hammer, his otters and a clue-bat • (Many otters • One bat • One hammer) 02:03, 7 November 2009 (UTC)

The fact tags are gone and additional refs have been added. This looks better now. The only thing I miss is a history section in which the two inline refs would perfectly fit in. --Stone (talk) 14:35, 9 November 2009 (UTC)

Missing information
I first learned of Raney Nickel by reading about it in Aldrichemica Acta, a publication of Aldrich Chemicals (now Sigma Aldrich and concentrating on Biochem; at sial.com). The newsletter noted that Raney products were patented (it sold to chemical industry as well as research in those days) and that the Raney term for hydrogen storage alloys applied to FeTi alloys as well as Nickel alloys. The Hydrogen storage of FeTi alloys was double the Ni alloys. The Aldrich reference and other patents dug up confirm that the general form of Raney Nickel alloys is MNi5 where M is Al, Ca, La, and a few others (NOT zinc, molybdenum and chromium), typically storing 5 H. I am familiar with Nickel electroplating and electroless Nickel plating (Hypophosphite as well as Borohydride methods); I've used Raney Nickel as well other catalysts in organic laboratory environments catalysts such as 5% Pd on C, PtO2/H2(100psi)or NiCl2/NaBH4. Nickel Boride (Ni2B) is NOT a Raney Nickel catalyst and is more effective at reducing ketones to alcohols.

Copper powder; used as 2.Cu + NaOH + H2O > NaCu(OH)2 + CuH and will add across the double bond in the enone form of recorcinol to form 1,3-cyclohexanedione (similar to the ionic sulfite ion), individually and not from the copper metal surface. CuH will react with acid H+ to form H2 and Cu+. Unless the compound being reduced is binding to the metal surface, and the Hydrogen Molecule is bound in close proximity, it is not being reduced in a manner similar to Raney catalysis. Devarda's alloy is not Raney's alloy.

The 'hydrogenation of vegetable oils', as listed in Murray Raney's patent, use higher temperatures (300 degrees) and very high Hydrogen pressures (10000psi). Raney Nickel loses activity when kept above room temperature. Note the ref that the higher activity of Raney Nickel promotes double bond migration so Raney Nickel is actually reducing the more labile diene (to the toxic Trans fats) than improving unactivated double bond hydrogenation. Other catalysts (e.g. copper chromite) have supplanted Nickel in part because they don't leave behind damaged product: Raney Nickel will also produce 3-phenyl-propyl-1-amine and 3-phenyl-propionaldehyde whereas Sodium Cyanoborohydride leaves only 3-phenyl-allyl amine from reductive amination of cinnamaldehyde.

The Hydrogen storage is a bulk property and not just a surface adsorbtion. Transition metals especially Group VIII can store significant Hydrogen within the lattice (leading to "Hydrogen embrittlement" and d10 elements notably Palladium so much so that solid metal disks are used to purify Hydrogen. (As a teen, I had a hydrogen balloon kit, CaH2 for generator. At a Testing Lab I worked at we had this type of Hydrogen purifier for the Flame Ionization Detector on our HP 5890 Gas Chromatograph; it was 5%Ag:Pd because At H:Pd over 1.7 there was a phase change in Pd lattice which caused it to shatter like in the Fleishman-Ponds experiments.) Platinum and Nickel also pass Hydrogen as as do Silver, Copper, and Iron to a lesser degree. Although diffusion rate of Hydrogen may be low at R.T.P. for many metals, it is much higher than than Helium and other noble gasses in metals. Helium diffuses much more rapidly than Hydrogen when in an unmetalized (Mylar) balloon. Those engineers that remember 'vacuum tubes' will remember the much higher diffusion rate of He, Ne, and even Argon through the glass envelope (very viscous liquid) of the vacuum tube compared to Hydrogen gas.

The energy of dissociation of the H2 hydrogen molecule is 104 Kcal/mole. The high heat generated by H-H recombination is used in specialized welding; it makes "Nacent Hydrogen" unlikely.

I have made and tested "rocket fuel" in a professional capacity. Non-hydrogen-containing metal powders such as Iron and Nickel are themselves pyrophoric. There was a warning by a company that makes Copper inkjet ink that the dry powder was flammable. NiAl alloy is typically sold as 325 mesh which particles becomes smaller as it is digested. 500 mesh Al or Mg can be mixed with inert material like sand and still catch fire (from static of turning the bottle) and burn in air/CO2/water. Re convenience: the slurry can be added via addition funnel with inert gas purge. We add heterogeneous materials to reactions all the time, Lithium Aluminum Hydride is a hazardous case in point yet used in 100 Kg sized industrial reactions.

Surface area on the label of commercial "Pd on C" catalyst listed 1000m2/gm which is what PdO2/H2 is supposed to give. Au can exist as a mono atomic colloid and the industrial Silver inkjet ink company says 2 to 8 atom clusters, from photography we know that the smallest stable Silver crystal is 2 atoms. Pt and Pd clusters are in the same range. From the Ni5M crystalography the Nickel clusters are an order of magnitude larger. From mechanism we know that 2nd and third row group VIII metals can cause organic reactions in one (metal) atom complexes yet the first row group VIII metals need 4 atoms along a specific plane('some' first row elements do 1 atom reductions like Ti, which is group IV, not VIII).

Refs:

Prep of Raney-Ni W2 and W6 see http://orgsyn.org/orgsyn/chemname.asp?nameID=33115

dissolving metal reaction alone and with added nickel salt Org. Synth. 1941, Coll. Vol. 1, 304 (see orgsyn.org)

Nickel Chloride and Borohydride 2,2' : 6',2' -TERPYRIDINE Org. Synth. 1990, Coll. Vol. 7, 476 (see orgsyn.org)

Nickel Boride http://pubs.acs.org/doi/abs/10.1021/jo00831a039

Advances in catalysis and related subjects By Walter G. Frankenburg http://books.google.com/books?id=f_Oiij4V98cC&pg=PA417&lpg=PA417&dq=raney+alloy+patent+nickel&source=bl&ots=VJnGCz3C-J&sig=uZ__XrvwATZovB72se83ImjP5ZU&hl=en&ei=XJ2rTba5CbPOiALGjKHvDA&sa=X&oi=book_result&ct=result&resnum=6&ved=0CEYQ6AEwBQ#v=onepage&q=raney%20alloy%20patent%20nickel&f=false

Murray Raney—Pioneer Catalyst Producer http://pubs.acs.org/doi/abs/10.1021/bk-1983-0222.ch034

Discovery and Development of Olefin Disproportionation (Metathesis) ROBERT L. BANKS ACS Symposium Series, Volume 222, pp 403–414 http://pubs.acs.org/doi/abs/10.1021/bk-1983-0222.ch029

FerroTitanium for hydrogen storage http://adsabs.harvard.edu/abs/1978aes.....8.3739J

Google patents US Pat. 2671336 - Filed Nov 30, 1949 "Palladium and platinum are materials which are permeable to hydrogen"

Lanthanum nickel hydride-hydrogen/metal oxide cell James D. Dunlop et al Patent number: 4112199 Filing date: Mar 28, 1977

Alloy for hydrogen storage electrodes Takaharu Gamo et al Patent number: 4946646 Filing date: May 16, 1988 http://www.google.com/patents?id=jwkhAAAAEBAJ&printsec=abstract&zoom=4#v=onepage&q&f=false

Solubility of hydrogen in solid Ni−Co and Ni−Cu alloys F. G. Jones and R. D. Pehlke http://www.springerlink.com/content/e471865737887132/

The role of hydrogen in dislocation generation in iron alloys James A. Clum "A material's susceptibility to hydrogen embrittlement can thus be viewed in terms of hydrogen adsorption energetics."

http://oai.dtic.mil/oai/oai?verb=getRecord&metadataPrefix=html&identifier=ADA113425 "susceptibility of nickel and nickel-base alloys to embrittlement by cathodically produced hydrogen. The transport of hydrogen by lattice and grain boundary diffusion, "

Shjacks45 (talk) 14:17, 18 April 2011 (UTC)

FAR needed
This article has numerous citation needed tags, and if anyone is working on or watching the article, I will also detail some prose concerns. Unless someone is willing to work on this article and correct the deficiencies, it should be submitted to WP:FAR. Have the sources listed above been consulted and incorporated if warranted? I'll check back in a week or so. Sandy Georgia (Talk) 03:29, 26 January 2012 (UTC)

Ra-Ni as catalyst?
Looking at the article in eEROS, Ra-Ni is not often used as a catalyst for anything. It's main reason for existence is apparently desulfurization. It would be useful to find out what kind of Ni is used industrially for hydrogenation, but I don't think that it is the Raney kind. Could be wrong though. For this article to be complete, we'd need a list of the various grades of Ra-Ni. --Smokefoot (talk) 22:56, 26 July 2012 (UTC)

The guy Raney developed Raney Nickel to make margarine, hydrogenation of vegetable oils. More active than finely divided Nickel by factor of thousands, requiring much lower Hydrogen pressure. TaylorLeem (talk) 20:42, 31 August 2020 (UTC)

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W.R. Grace owner of Raney patents
"Raney® Catalysts Grace Davison's Raney® catalyst family is an efficient class of catalyst available for numerous organic processes including hydrogenations, ammonolysis, reductive alkylation and dehydrogenations.  They are available in both slurry and fixed bed form.  They are usually made from nickel, cobalt, and copper base metals.  Various promoter metals (molybdenum, chromium, iron, etc.) can be added to the base metals to affect selectivity and activity.  With their high activity and selective characteristics, Raney® catalysts can be an effective and economically attractive catalyst to increase process throughput while decreasing byproduct formation.  Read on to find out more about general selection guidelines, description of Raney® catalysts, and key benefits of Raney® catalysts, or check out our selection of products:" TaylorLeem (talk) 21:30, 31 August 2020 (UTC)

Nickel Metal Hydride batteries
Raney Nickel is the "Metal Hydride" of Nickel Metal Hydride batteries. A significant application. Also NiMH batteries are used in Japanese Hybrid vehicles. 75.253.119.222 (talk) 01:28, 6 July 2024 (UTC)