This study investigates the mechanism of concentrated light in the photothermal CO

2

methanation process using a highly reactive Ni/Al

2

O

3

catalyst with excellent photothermal conversion characteristics experimental investigations were performed under concentrated photothermal and thermal driven conditions to shed light on the reaction mechanism. Apparent activation energy tests

temperature gradient experiments and time-resolved in-situ diffuse reflectance infrared spectroscopy experiments were c

onducted

to gain insights into the process. The results demonstrate that the photothermal-driven process outperforms the thermal-driven process

exhibiting superior catalytic performance at the same temperature. Remarkably

a Ni/Al

2

O

3

catalyst containing 15% mass fraction of Ni achieved an impressive CO

2

conversion rate of 86.8% at 350 ℃ under the photothermal-driven condition. Notably

the photothermal-driven process required a 25 ℃ lower temperature to achieve the highest CO

2

conversion rate compared to the thermal-driven process. The apparent activation energy of the photothermal-driven process was reduced by 25%

and the concentrated light-induced temperature gradient further enhanced CO

2

conversion. Time-resolved in-situ diffuse reflectance infrared spectroscopy experiments showed that concentrated light improved CO

2

adsorption on the catalyst surface

promoted the transformation of key intermediates

and enhanced the reaction pathway of CO

*

to CH

4

thereby enhancing CO

2

conversion at a microscopic level. This study provides valuable insights into the role of concentrated light in CO

2

methanation driven by concentrated solar energy

shedding light on the underlying mechanism.