*2.3. Catalyst Testing*

Catalyst activity measurements were carried out using a Process Integral Development Engineering and Technology (PID Eng & Tech) Microactivity Setup equipped with a tubular stainless steel fixed-bed reactor (9 mm I.D., Autoclave Engineers, Pennsylvania, USA). The effluent gases were analyzed by an on-line gas chromatograph (GC, ALPHA MOS instrument, Toulouse, France) with a thermal conductivity detector at an interval of 30 min. For separation of the products, two GC columns Molecular Sieve 5A and Porapak Q were employed in series/bypass connections. A catalyst load of 0.15 g was used for each run while the total gas flow was fixed at 15 mL/min. Prior to the reaction the catalyst was reduced by dosing H<sup>2</sup> at a flow rate of 40 mL/min. The temperature was kept at 800 or 700 ◦C and held for 1 h in order to reduce the metal oxide into the active metal. Afterwards, the reactor was purged with N<sup>2</sup> till the required reaction temperature was achieved. The feed is not introduced to the reactor unless H<sup>2</sup> is completely removed from the system. This is done using GC analysis via TCD detector. A propak Q and molecular sieve columns were used for separation. The volume ratio of feed gases (CH4/O2) was set to 2. In addition, the space velocity was held at 6000 mL/(h·gcat), while the total feed rate was set to 15 mL/min. The reaction temperature was checked by placing a thermocouple in the middle of the catalyst bed and the bed height was 0.4 cm. The reforming activity of catalysts was studied at 700 and 800 ◦C at 1 bar.

The composition of effluent gases was calculated by the normalization method, and the equations for determination of conversion and selectivity are used as following:

$$\text{Conversion of CH}\_4: \text{ X}\_{\text{CH}4} = \frac{\text{CH}\_4 \text{ in} - \text{CH}\_4 \text{ out}}{\text{CH}\_4 \text{ in}} \times 100\% \tag{7}$$

$$\text{Selocity of H}\_2: \text{ S}\_{\text{H}2} = \frac{\text{moles of H}\_2 \text{ produced}}{\text{Total moles of products } (\text{H}\_2 + \text{H}\_2\text{O})} \times 100\% \tag{8}$$

$$\text{Selocity of CO} : \text{S}\_{\text{CO}} = \frac{\text{moles of CO produced}}{\text{Total moles of products (CO} + \text{CO}\_2)} \times 100\% \tag{9}$$
