Table B.2.

Summary of all collision-based energy transitions (reactions), their energy difference $∆E$ and respective reaction rate k for the complete de-excitation process during photoacoustic methane detection with regards to gas matrices containing nitrogen, oxygen and water (see Fig. 7).

	Reaction	$\mathbf{d}\mathit{E}$in cm−1	Reaction ratekin s−1atm−1 used literature
$\left(1\right)$	${\mathrm{CH}}_4\left({\nu }_{{\mathrm{s}}_1}\right)+M\stackrel{k_1^M}{\to }{\mathrm{CH}}_4\left(2{\nu }_{\mathrm{b}}\right)+M$	$-124$	$k_1^{{\mathrm{CH}}_4}=2.1·{10}^8$	$2.1·{10}^8$[32]
			$k_1^{{\mathrm{N}}_2}=4.6·{10}^8$	$4.6·{10}^8$[33]
			$k_1^{{\mathrm{H}}_2\mathrm{O}}=1·{10}^8$	$/$
			$k_1^{{\mathrm{O}}_2}=4.6·{10}^8$	$4.6·{10}^8$[33]
$\left(2\right)$	${\mathrm{CH}}_4\left(2{\mathrm{\nu }}_{\mathrm{b}}\right)+{\mathrm{CH}}_4\stackrel{k_2}{\to }{\mathrm{CH}}_4\left({\mathrm{\nu }}_{\mathrm{b}}\right)+{\mathrm{CH}}_4\left({\mathrm{\nu }}_{\mathrm{b}}\right)$	$0$	$k_2=5·{10}^8$	$5.5·{10}^8$[34]
$\left(3\right)$	${\mathrm{CH}}_4\left(2{\mathrm{\nu }}_{\mathrm{b}}\right)+{\mathrm{H}}_2\mathrm{O}\stackrel{k_3}{\to }{\mathrm{CH}}_4\left({\mathrm{\nu }}_{\mathrm{b}}\right)+{\mathrm{H}}_2\mathrm{O}\left({\mathrm{\nu }}_2\right)$	$173$	$k_3=1·{10}^8$	$/$
$\left(4\right)$	${\mathrm{CH}}_4\left(2{\mathrm{\nu }}_{\mathrm{b}}\right)+{\mathrm{O}}_2\stackrel{k_4}{\to }{\mathrm{CH}}_4\left({\mathrm{\nu }}_{\mathrm{b}}\right)+{\mathrm{O}}_2\left(\mathrm{\nu }\right)$	$134$	$k_4=1·{10}^7$	$6.6·{10}^6$[34]
$\left(5\right)$	${\mathrm{CH}}_4\left(2{\mathrm{\nu }}_{\mathrm{b}}\right)+M\stackrel{k_5^M}{\to }{\mathrm{CH}}_4\left({\mathrm{\nu }}_{\mathrm{b}}\right)+M$	$-1422$	$k_5^{{\mathrm{CH}}_4}=1.6·{10}^6$	$1.6·{10}^6$[35]
			$k_5^{{\mathrm{N}}_2}=2·{10}^5$	$1.6·{10}^5$[35]
			$k_5^{{\mathrm{H}}_2\mathrm{O}}=2.4·{10}^5$	$/$
			$k_5^{{\mathrm{O}}_2}=2.6·{10}^5$	$/$
$\left(6\right)$	${\mathrm{CH}}_4\left({\mathrm{\nu }}_{\mathrm{b}}\right)+{\mathrm{H}}_2\mathrm{O}\stackrel{k_6}{\to }{\mathrm{CH}}_4+{\mathrm{H}}_2\mathrm{O}\left({\mathrm{\nu }}_2\right)$	$173$	$k_6=7·{10}^7$	$/$
$\left(7\right)$	${\mathrm{CH}}_4\left({\mathrm{\nu }}_{\mathrm{b}}\right)+{\mathrm{O}}_2\stackrel{{\mathrm{k}}_7}{\to }{\mathrm{CH}}_4+{\mathrm{O}}_2\left(\mathrm{\nu }\right)$	$134$	$k_7=2·{10}^6$	$3.3·{10}^6$[34]
$\left(8\right)$	${\mathrm{O}}_2\left(\mathrm{\nu }\right)+{\mathrm{H}}_2\mathrm{O}\stackrel{k_8}{\to }{\mathrm{O}}_2+{\mathrm{H}}_2\mathrm{O}\left({\mathrm{\nu }}_2\right)$	$39$	$k_8=2.2·{10}^7$	$2.2·{10}^8$[36]
$\left(9\right)$	${\mathrm{O}}_2\left(\mathrm{\nu }\right)+{\mathrm{CH}}_4\stackrel{k_9}{\to }{\mathrm{O}}_2+{\mathrm{CH}}_4\left({\mathrm{\nu }}_{\mathrm{b}}\right)$	$-134$	$k_9=3.3·{10}^7$	$3.3·{10}^7$[34]
$\left(10\right)$	${\mathrm{H}}_2\mathrm{O}\left({\mathrm{\nu }}_2\right)+{\mathrm{CH}}_4\stackrel{k_{10}}{\to }{\mathrm{H}}_2\mathrm{O}+{\mathrm{CH}}_4\left({\mathrm{\nu }}_{\mathrm{b}}\right)$	$-173$	$k_{10}=2·{10}^7$	$/$
$\left(11\right)$	${\mathrm{H}}_2\mathrm{O}\left({\mathrm{\nu }}_2\right)+{\mathrm{O}}_2\stackrel{k_{11}}{\to }{\mathrm{H}}_2\mathrm{O}+{\mathrm{O}}_2\left(\mathrm{\nu }\right)$		$k_{11}=2·{10}^7$	$3.8·{10}^7$[37]
$\left(12\right)$	${\mathrm{CH}}_4\left({\mathrm{\nu }}_{\mathrm{b}}\right)+M\stackrel{k_{12}^M}{\to }{\mathrm{CH}}_4+M$	$-1422$	$k_{12}^{{\mathrm{CH}}_4}=8·{10}^5$	$8·{10}^5$[34]
			$k_{12}^{{\mathrm{N}}_2}=4.5·{10}^4$	$8·{10}^4$[35]
			$k_{12}^{{\mathrm{H}}_2\mathrm{O}}=1.2·{10}^5$	$/$
			$k_{12}^{{\mathrm{O}}_2}=7·{10}^4$	$1.4·{10}^5$[34]
$\left(13\right)$	${\mathrm{H}}_2\mathrm{O}\left({\mathrm{\nu }}_2\right)+M\stackrel{k_{13}^M}{\to }{\mathrm{H}}_2\mathrm{O}+M$	$-1595$	$k_{13}^{{\mathrm{CH}}_4}=1·{10}^6$	$/$
			$k_{13}^{{\mathrm{N}}_2}=1·{10}^7$	$1·{10}^6$[36]
			$k_{13}^{{\mathrm{H}}_2\mathrm{O}}=1.2·{10}^9$	$1.2·{10}^9$[38]
			$k_{13}^{{\mathrm{O}}_2}=1·{10}^6$	$1·{10}^6$[36]
$\left(14\right)$	${\mathrm{O}}_2\left(\mathrm{\nu }\right)+M\stackrel{k_{14}^M}{\to }{\mathrm{O}}_2+M$	$-1556$	$k_{14}^{{\mathrm{CH}}_4}=1·{10}^6$	$1·{10}^6$[39]
			$k_{14}^{{\mathrm{N}}_2}=18$	$18$[40]
			$k_{14}^{{\mathrm{H}}_2\mathrm{O}}=1.1·{10}^6$	$8·{10}^5$[36]
			$k_{14}^{{\mathrm{O}}_2}=81$	$81$[38]