Dario Campisi shows mineral surfaces promote formamide formation

Dario Campisi used density functional theory (DFT), a quantum-chemical method, to show that formamide can form on Mg(OH)2·H2O and bare (010) forsterite (Mg2SiO4) surfaces, submitting the study on Nov. 4, 2026, for publication in Astronomy & Astrophysics, according to Astrobiology Web.

Astrobiology Web reports that the quantum-chemical investigation examined how NH2 adds to formaldehyde on an isolated Mg(OH)2·H2O molecular model and on the forsterite (010) surface. The researcher benchmarked theoretical methodologies before testing the two mineral models, then computed kinetics for cases with an entrance barrier.

Formamide formation matters because the compound serves as a precursor to amino acids and RNA, though how it forms in the Universe remains debated, Astrobiology Web reports. Current studies of cosmic formamide focus on gas-phase and icy grain formation routes.

The paper contrasts these established routes with the mineral-surface pathway it examines. Formation on bare silicate surfaces or hydrated magnesium-bearing molecular models remains largely unexplored in protoplanetary disk environments. The gap motivated the investigation of these two mineral surfaces as dust-grain analogs in settings relevant to protoplanetary disks.

Astrobiology Web reports that these mineral surfaces are candidates for promoting prebiotic chemistry in protoplanetary disk environments, where surface-based formation routes had not been well explored. On the bare forsterite (010) surface, which stands in for a bare dust-grain surface, NH2 addition to formaldehyde follows a barrier-less pathway when NH2 is initially physisorbed (loosely bound to the surface) near the formaldehyde center. Proton transfer then leads to formamide formation. The source contrasts this barrier-less silicate route with the proton-transfer mechanism on the hydrated magnesium model (Mg(OH)2·H2O).

On the magnesium hydroxide hydrate model, proton transfer within the intermediate occurs through an O-H group coordinated with magnesium, Astrobiology Web reports. The reaction step from the pre-reactive complex is predicted to happen on nanosecond timescales at temperatures approaching 300 K. The kinetic estimate shows that proton transfer in the hydrated magnesium system is rapid near room temperature.

Astrobiology Web reports that Campisi concluded that both magnesium-bearing model systems promote rapid proton transfer after NH2 addition to formaldehyde. The work supplies kinetic data for astrochemical models by computing unimolecular rate constants and half-lives for cases with an entrance barrier. These calculations were performed specifically to assess kinetic behavior where an entrance barrier exists.

The paper runs 18 pages with 10 figures, Astrobiology Web reports. Dario Campisi is the author and submitter, with version 1 appearing in the submission history.