I am reading a paper that contains the line:
Most of the $\small H_2$ in the Earth's mantle escaped to space early in the Earth's history; consequently, the overwhelming majority of the abiotic geochemical reactions are based on acid/base chemistry, i.e., transfers of protons without electrons.
The connection between the loss of $\small H_2$ and acid/base chemistry is not clear to me.
Why would the loss of $\small H_2$ to space make acid/base chemistry the default?
- Falkowski, P. G., T. Fenchel, and E. F. Delong. (2008) The microbial engines that drive Earth's biogeochemical cycles. Science 320:1034-1038.