Study of the M-doped Effect (M=Al, Ag, W) on the Dissociation of O2 on Cu Surface Using a First Principles Method

Abstract

The O 2 adsorption and dissociation on M-doped (M=Al, Ag, W) Cu ( 111) surface were studied by density functional theory. The adsorption energy of adsorbate, the average binding energy and surface energy of Cu surface, and the doping energy of doping atom were calculated. All the doped atoms can be stably combined with Cu atoms and improve the surface activity of Cu surface, while the Al and W atoms would strengthen the bonding effect between the atoms on the Cu (111) slab except Ag doping atom. Due to the different electronegativity of three metals of Al, Ag, W, these doping atoms can resist the dissociation of O 2 by DOS analysis. The potential energy surface was computed, and the result showed that the dissociation reaction of O 2 on the surfaces not only reflected in the barrier energy, but also the reaction energy. Ag atoms had the best resistance effect on the O 2 dissociation comparing with Al and W atoms because of the large barrier energy and reaction energy.

Impact of irradiance and inorganic carbon availability on heterologous sucrose production in Synechococcus elongatus PCC 7942

“…At ~140 mOsm, CD medium has an osmolarity that is approximately 3-fold higher than that of BG-11 alone and can provide osmotic pressure equivalent to BG-11 supplemented with ~50 mM NaCl. The strain in this study produces sucrose utilizing a heterologous salt-independent SPS; however, increased salt or osmotic stress engages the endogenous salt-dependent sucrose production pathways and has been shown to lead to a higher diversion of fixed carbon toward sucrose biosynthesis (Ducat et al, 2012;Kirsch et al, 2019;Liang et al, 2020). Sucrose exporters grown in CD media produced 139% more sucrose than their BG-11 counterparts by 72 hours, and a total of 1.8 g L -1 sucrose by 120 h (Figure 2D).…”