I think, more accurately, a thin layer effect. "Surface" is kind of a nebulously defined thing. IIRC, one of the earliest claims to high output was by an ex-Dow Chemical electrochemist (Patterson??), who used a palladium layer on plastic beads. Not exactly a high temperature system.
Patterson was a classic tragic cold fusioneer. Once he started getting high COPs, he saw thought he was gonna be a trillionaire. He kept all his data to himself. And then he died, burying his secrets with him. Not exactly someone in it for the science.
My theory is that it is a linear lattice effect.
On the skin of materials ,the very top nano layer of atoms are a jumbled mess, like an orchard hit by a tsunami. Once you get past those destroyed trees, you see the symmetry and crystalline structure of the orchard. Even a blind man could walk in the same direction for a mile.
Once the hydrogen or deuterium gets absorbed into the linear crystalline structure of the bulk lattice host metal just a few atoms beneath the surface, it starts dancing back & forth in a line inside its linear crystalline cage. Then it gets joined by another H or D atom doing the same linear dance. Then another and another until there’s maybe a hundred or a thousand linear dancing hydrogen/deuterium atoms bouncing into each other,
Eventually these back&forth dancing atoms start to move in sync with each other, forming a linear Bose-Einstein Condensate [BEC]. Inside a BEC, the Coulomb Barrier almost drops completely, making fusion events much much more likely.
Significantly, some of rhe highest COPs are seen when the Lattice is COOLED before the reaction. BECS are formed at low temperatures.
When researchers use H1 gas instead of H2 gas, they are inducing a chemical change that Hydrogen wants to do before anything else, it wants to meet up with a nearby H1 atom to form H2 gas in an ENDOthermic reaction, cooling the surrounding lattice. Another example is what K P Sinha & Meulenberg did, they laser-COOLED a lattice to begin the reactions. President Clinton’s science advisor Steven Chu got a Nobel Prize for using lasers to cool atoms to form BECs.
That’s the gist of my V1DDLLBEC theory — Vibrating 1 Dimensional Luttinger Liquid Bose Einstein Condensate.
1 Dimensional LENR Theories
https://www.lenr-forum.com/forum/thread/5859-1-dimensional-lenr-theories/
thread started by yours truly
I think I might reproduce this thread over here at some point