Rhodium unique metal characteristics.

[SilverPlatinum]

I have been doing a research on Rhodium to justify the current high price of this special metal. I have found the below info, please add anything you can think of.

Rhodium unique metal characteristics:

1***  The 2nd highest metal reflective of light (visible spectrum). But since It does not corrode or tarnish by the atmosphere at room temperature therefore it can be the 1st reflective of light (because silver tarnishes in room temperature). Here are the top 3 reflective metals at different wavelengths spectrum:
1) Silver.
2) Rhodium.
3) Platinum.
This is why they plate some Jewelry with Rhodium (since silver would tarnish, and Platinum is just a slightly lower in reflection than Rhodium at some wavelength spectrum).

2*** It conducts electricity better than any other platinum-group metal (PGMs) which are Platinum, Palladium, Rhodium, Ruthenium, Iridium, and Osmium. This is why it's used in a critical devices like the heart pacemakers and spaceships devices.

3*** Of the three precious metals (Rhodium, Platinum and Palladium) currently used in vehicle catalytic converters, Rhodium has by far the highest activity for the removal of nitrogen oxides (NOx) from the exhaust. It also has very high activity for the oxidation of hydrocarbons (HC) and carbon monoxide (CO) and very good resistance to the poisons present in the exhaust.

4*** Swiss researchers at the Paul Scherrer Institute (PSI) and the ETH Zurich developed a new chemical process that uses the sun's thermal energy to convert carbon dioxide and water into high energy fuels. This chemical process involves a new material combination of cerium oxide and small amounts of Rhodium as a catalyst. Their discovery is a major step toward the chemical storage of solar energy (which has been a very tricky problem for scientists).
https://pubs.rsc.org/en/Content/ArticleLanding/2016/EE/C6EE00862C