Direct Visualization of CO Interaction on Oxygen Poisoned Co(0001)

The poisoning of catalysts has always been a vital issue in catalytic reactions. In this study, direct observation of the interaction of CO and oxygen-poisoned Co(0001) has been achieved with scanning tunneling microscopy (STM), temperature-programmed desorption (TPD), and density functional theory calculation. A two-stage adsorption process of CO on a well-prepared p(2×2)-O layer covered Co(0001) was directly visualized. With increasing annealing time at a certain temperature after the CO dosage, the ordered (2 × 2) pattern formed in the first stage can be recovered, suggesting the weak interaction of CO with the O-covered Co(0001) surface in the latter stage. Compared to the clean Co(0001) surface, on an oxygen-poisoned surface, no further reaction was observed, illustrating the poisoning of the catalyst. Moreover, TPD results are in good agreement with the STM observation; a desorption energy of 0.35 eV is evaluated with a simple but accurate scheme.

A Review on Green Hydrogen Valorization by Heterogeneous Catalytic Hydrogenation of Captured CO2 into Value-Added Products

The catalytic hydrogenation of captured CO2 by different industrial processes allows obtaining liquid biofuels and some chemical products that not only present the interest of being obtained from a very low-cost raw material (CO2) that indeed constitutes an environmental pollution problem but also constitute an energy vector, which can facilitate the storage and transport of very diverse renewable energies. Thus, the combined use of green H2 and captured CO2 to obtain chemical products and biofuels has become attractive for different processes such as power-to-liquids (P2L) and power-to-gas (P2G), which use any renewable power to convert carbon dioxide and water into value-added, synthetic renewable E-fuels and renewable platform molecules, also contributing in an important way to CO2 mitigation. In this regard, there has been an extraordinary increase in the study of supported metal catalysts capable of converting CO2 into synthetic natural gas, according to the Sabatier reaction, or in dimethyl ether, as in power-to-gas processes, as well as in liquid hydrocarbons by the Fischer-Tropsch process, and especially in producing methanol by P2L processes. As a result, the current review aims to provide an overall picture of the most recent research, focusing on the last five years, when research in this field has increased dramatically.