Science Magazine recently published this article about Prof. Roy Periana (Scripps Florida) to much pomp and circumstance. I have previously addressed my thoughts on his recent work, and the fact that this has now also been covered in Science leaves me seriously puzzled and disappointed. I don’t have anything personal against Prof. Periana, but I am for the dissemination of good science (as opposed to marketing and hype). I will admit that with my limited knowledge, I am not the most qualified person to judge “good” from “bad” science, but I do want the public to have the correct impression of the state-of-the art in chemistry, based on current facts.
The introduction gets the facts correct; a process to efficiently and catalytically convert methane (CH4, the primary component of natural gas) to methanol (CH3OH, the simplest alcohol) would upturn the petrochemical industry. Methanol can be used as a primary fuel and also serves as a more convenient synthetic feedstock to fine chemicals and other higher hydrocarbons. This is the basis of the “Methanol Economy“, as propounded by Profs. George Olah and G. K. Surya Prakash. Another, slightly different approach, is the reductive approach starting from carbon dioxide (CO2).
In the 70’s, Prof. Olah discovered that the use of common oxidants (such as H2O2 or O3) in newly discovered superacid systems (such as HF-SbF5 or FSO3H-SbF5, also called Magic Acid) led to the selective oxidation of methane to methanol, a holy grail of hydrocarbon chemistry. This occurs due to the immediate protonation of methanol in the medium to form the methyloxonium ion. The proton serves as a “protecting group”, preventing further oxidation in the medium.
Periana’s work is therefore best viewed as a modification of Prof. Olah’s pioneering discoveries. The use of metal salts allows the reaction to be conducted in weaker acids (such as sulfuric acid). Now, it has been found that TFA (trifluoroacetic acid, which is about 10-10 times weaker than sulfuric acid) in conjuction with thallium or lead salts also promotes this reaction. The downsides, as I have mentioned before, are that the Tl and Pb salts required are toxic, expensive, and required in stoichiometric amounts. Also, another aspect not mentioned is that this reaction only generates alkyl trifluoroacetic esters, requiring an extra hydrolysis step to generate the desired alcohol (which then also has to be separated from the acid so produced).
The last paragraph, however, made me facepalm. Science made the same statement that C&EN made a few months ago: “It appears that some venture capitalists agree. Periana says he’s already seen interest from investment firms and large chemical companies in starting a company to develop the technology. If it works, Periana will finally achieve his goal of cheaply tweaking his favorite chemical bond, and just maybe change the world in the process.”
Again, if there are VC’s out there who lack even a modicum of chemistry knowledge and are moronic enough to fund this enterprise…then yes, the world will be changed rather irreversibly by widespread thallium and lead poisoning.
It’s articles like these (based on hype rather than facts) that make me ashamed to call myself a chemist in this day and age…