The MIA research report cited by the OP is almost certainly this one:
Diamond Formation by Reduction of Carbon Dioxide at Low Temperatures
Zhengsong Lou, Qianwang Chen, Yufeng Zhang, Wei Wang, Yitai Qian
J. Am. Chem. Soc. 2003, 125, 31, 9302-9303
Publication Date:July 11, 2003
https://doi.org/10.1021/ja035177i
Abstract
This Communication reports a low-temperature diamond synthesis technique, in which diamonds (10−250 μm) can form at a temperature as low as 440 °C by reduction of dense CO2 with metallic Na. The X-ray diffraction pattern of a powder sample shows three reflection peaks, indexed with 111, 220, and 311, corresponding unambiguously to cubic diamond. The Raman spectrum of the product exhibits an intense first-order peak at 1332 cm-1, which is the characteristic signature of the cubic diamond, indicating the formation of well-crystallized diamond. Carbon dioxide is a nontoxic low-energy molecule, abundant on earth. This novel reduction method could allow studies of large-size diamond growth using CO2 as the carbon source
SOURCE:
https://pubs.acs.org/doi/full/10.1021/ja035177i
