Made from methanol

An unusual pathway in the reaction of various transition metal atoms with methanol leads to the direct production of hydrogen.

Credit: © 2010 Wiley

Although it is unclear whether a new energy economy based on hydrogen or methanol will solve current fossil-fuel-related problems, there is great interest in developing methods of efficiently converting hydrocarbons and alcohols to hydrogen. Now Jun Li at Tsinghua University, Mingfei Zhou at Fudan University and colleagues have uncovered¹ an unexpected reaction route for the production of hydrogen from the reaction of methanol with early transition metal atoms

They recorded the infrared spectrum of vanadium atoms co-deposited with a methanol–argon mixture at cryogenic temperatures. After annealing at 35 K, the previously observed peaks associated with V(CH₃OH) complexes were supplemented with extra peaks. Repeating the co-deposition and annealing with isotopically labelled methanol allowed the peaks to be identified as being from the low-valent V(OCH₃) — rather than the more expected high-valent H₂V(OCH₃) — suggesting that hydrogen was being produced. Density functional theory calculations were used to simulate the infrared spectra of V(OCH₃) and these agreed well with the experiments. Li and colleagues also calculated the potential energy surface for the reaction, revealing that it is thermodynamically favourable and proceeds via two transition states.

The experiments were also carried out with scandium, niobium and titanium and gave similar results, showing that hydrogen can be directly produced from the reaction of metal atoms with methanol. This gives a possible new direction for research on catalytic hydrogen production from methanol.