${\text{CH}}_2={\text{CH}}_2=+{\text{H}}_{\text{2}}\stackrel{{\text{Pt,T}}_{\text{1}}\text{K}}{\to }{\text{C}}_{\text{2}}{\text{H}}_{\text{6}}{\text{CH}}_2={\text{CH}}_2+{\text{H}}_2\stackrel{{\text{Ni,T}}_{\text{2}}\text{K}}{\to }{\text{C}}_{\text{2}}{\text{H}}_{\text{6}}$

The correct relation among the following is

Alkenes combine with hydrogen under pressure and in presence of a catalyst to form alkanes. This process is known as catalytic hydrogenation. With nickel catalyst, temperature of about $200-300°\text{C}$and in presence of Pt or Pd, even at room temperature, hydrogenation occurs.

$\therefore {\text{T}}_2>{\text{T}}_1$