# What is the origin of the names P-1 and P-2 of nickel boride catalysts?

From Chapter 2 of Catalytic Hydrogenation in Organic Syntheses:

Highly stereospecific hydrogenations of acetylenes to cis-olefins can be achieved with a nickel (P2) catalyst, prepared by sodium borohydride reduction of nickel acetate in ethanol, and ethylenediamine as a promoter.

The Wikipedia article on nickel boride describes two forms, P-1 and P-2, differing in their ratio of $\ce{Ni2B}$ to $\ce{NaBO2}$.

What is the origin of the names "P1" and "P2"? Does it have to do with whether the catalysts add hydrogen in a syn or anti fashion?

• Have a look at Wikipedia, it's right there: en.wikipedia.org/wiki/Nickel_boride#Preparation – Pritt says Reinstate Monica May 20 '17 at 12:22
• The meaning of ''p -2" , the reason behind this terminology is what I wanted to know. – Iype Eldho May 21 '17 at 18:12
• I'm speculating things: the only google books reference I'm able to find is this (it's not letting me preview the entire book). Notice closely, Raney Nickel has been called W2, and a footnote at this wikipedia article tells me that's a grade of nickel. So, perhaps P2 is also a grade? – Berry Holmes May 22 '17 at 7:38