Figure 4: Influence of temperature on the hydrogenation of CO2 to formic acid using [RuCl2(PTA)4] as the catalyst: 90 °C (brown circle), 60 °C (red diamond), 50 °C (blue square), 40 °C (green asterisk) and 30 °C (pink triangle).
From: Direct synthesis of formic acid from carbon dioxide by hydrogenation in acidic media