## 2 Experimental Investigations  
### Equipment and Materials  
A catalytic infrared equipment setup was constructed, including a catalytic infrared radiator system, a gas supply system, an electric control system, a temperature measurement system, and the main body of the equipment, as displayed in Figure 2. The radiation plate (800 \(\times\) 400 \(\times\) 50 mm) used in the experiment is shown in Figure 3, and its maximum power was 4 kW. Two catalytic infrared radiation panels were located on top of the equipment. The bottom platform was insulated and equipped with a base frame to prevent heat transfer between the coating sample and the platform. A control cabinet was used to adjust the distance between the radiation panels and the sample. During the curing process, the samples' temperatures and the air inside the equipment were measured using  
Figure 1: Research framework.  
K-type thermocouples. We set one temperature measurement point centered at the top of the samples and one centered at the bottom. The temperature signals were transmitted to a computer. A portable infrared thermometer was used to measure the temperature at the panel's surface in real time. The gas used in this experiment was liquefied petroleum gas (LPG) from a tank. The details of the experimental instruments are shown in Table 1.  
Figure 3: Catalytic infrared radiation panel.  
Figure 2: (**a**) Catalytic infrared curing oven. (**b**) Schematic diagram of infrared curing furnace with catalytic combustion.  
The catalyst used in this study was prepared using high-temperature calcination with fibrous alumina as the carrier and platinum and other trace metal components, as shown in Figure 4a. The characteristics of this catalyst are summarized in Table 2. The changes in the methane conversion rate with temperature under the action of the catalyst provided by Suzhou Catalytic Green Energy Co., Ltd. (Suzhou, China) are shown in Figure 4b. The Cat-1 catalyst exhibited a more effective ability to transform methane than the Cat-2 catalyst, so Cat-1 was used in this study.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Name** & **Picture** & **Model** & **Range** & **Precision** & **Error** \\ \hline K-Type thermocouple & & WRNT-01 & \(-\)200–500 \({}^{\circ}\)C & 0.1 & 0.5\% \\ Temperature logger & & KCM-LCD16 & \(-\)30–1300 \({}^{\circ}\)C & 0.1 & - \\ Infrared thermometer & & MS Plus & \(-\)32–530 \({}^{\circ}\)C & 0.1 & 1\% \\ Gloss meter & & HG60 & 0–300 GU & 0.1 & 0.2\% \\ Universal colorimeter & & NR10 QC & L* 0–100 a*, b* \(-\)100–100 & 0.01 & 0.03\% \\ \hline \hline \end{tabular}
\end{table}
Table 1: Details of the experimental instruments.  
Figure 4: (a) Fiber-supported noble metal catalyst. (b) Methane conversion versus temperature with the Cat-1 and Cat-2 catalysts.  
The powder coating used in this study was a triglyceride isocyanate (TGIC) polyester system (provided by Jiangsu Aiyue Powder Coating Co., Ltd., Taicang, China), which is widely used in the metal coating industry. The characteristics of this powder coating are summarized in Table 3. The substrates were test-grade galvanized steel panels, and the size of these plates was 150 \(\times\) 70 \(\times\) 1 mm. The powder coating was sprayed with a high-voltage electrostatic spray gun, and the thickness of the paint film was controlled at 100 \(\upmu\)m.