Optical properties and corrosion resistance of Ti2AlC, Ti3AlC2, and Cr2AlC as candidates for Concentrated Solar Power receivers

TL;DR

This study evaluates MAX phase materials Cr2AlC, Ti2AlC, and Ti3AlC2 for use in concentrated solar power receivers, focusing on their optical properties and corrosion resistance in molten salt environments.

Contribution

It provides new data on the optical and corrosion resistance properties of MAX phases, highlighting Cr2AlC as a promising candidate for CSP applications.

Findings

Cr2AlC shows superior corrosion resistance due to a protective nanometric layer.

All three MAX phases have high solar absorptance (>0.5) and low thermal emittance (0.17-0.31).

Cr2AlC maintains properties after 4 weeks of molten salt exposure.

Abstract

New generation concentrated solar power (CSP) plants require new solar receiver materials with selective optical properties and excellent corrosion resistance against molten salts. MAX phases are promising materials for CSP applications due to their optical properties and resistance to thermal shocks. Herein, we report a solar absorptance >/= 0.5 and a thermal emittance of 0.17-0.31 between 600 and 1500 K for Cr2AlC, Ti2AlC, and Ti3AlC2. These compositions were also exposed to solar salt corrosion at 600{\deg}C for up to 4 weeks. Cr2AlC exhibited superior corrosion resistance due to the formation of a protective nanometric layer.