Enhancement of the yield of poly (ethylene terephthalate) hydrolase production using cell membrane protection strategy.

Biodegradation, particularly via enzymatic degradation, has emerged as an efficient and eco-friendly solution for Poly (ethylene terephthalate) (PET) pollution. The production of PET hydrolases plays a role in the large-scale enzymatic degradation. However, an effective variant, 4Mz, derived from Thermobifida fusca cutinase (Tfu_0883), was previously associated with a significant reduction in yield when compared to the wild-type enzyme.

Directional-path modification strategy enhances PET hydrolase catalysis of plastic degradation.

Poly (ethylene terephthalate) (PET) is a widely used type of general plastic that produces a significant amount of waste due to its non-degradable properties. We propose a novel directional-path modification (DPM) strategy, involving positive charge amino acid introduction and binding groove remodeling, and apply it to Thermobifida fusca cutinase to enhance PET degradation. The highest value of PET degradation (90%) was achieved in variant 4Mz (H184S/Q92G/F209I/I213K), exhibiting values almost 30-fold that of the wild-type.

Effect of point defects on acetylene hydrogenation reaction over Ni(111) surface: a density functional theory study.

Density functional theory (DFT) calculations are carried out to investigate the effect of point defects on acetylene hydrogenation reaction over Ni(111) surface with three different defect concentrations (DC = 0.0500, 0.0625, and 0.

Theoretical study on the reaction mechanism and selectivity of acetylene semi-hydrogenation on Ni-Sn intermetallic catalysts.

Recently, Ni-Sn intermetallic compounds (IMCs) with unique geometric structures have been proved to be selective catalysts for acetylene hydrogenation to ethylene, but the origin of the selectivity remains unclear. In this work, a density functional theory (DFT) study has been carried out to investigate the mechanism of acetylene hydrogenation on six surfaces of Ni-Sn IMCs, and the geometric effects towards ethylene selectivity were revealed. Two key parameters (adsorption energy and the hydrogenation barrier of ethylene), which determine the ethylene selectivity, were studied quantitatively.

The reaction mechanism and selectivity of acetylene hydrogenation over Ni-Ga intermetallic compound catalysts: a density functional theory study.

Intermetallic compounds (IMCs) have shown excellent catalytic performance toward the selective hydrogenation of acetylene, but the theoretical understanding on this reaction over Ni-based IMCs is rather limited. In this work, the adsorptions of the C species, Bader charge, projected density of states (PDOS) and the reaction pathways were calculated by the density functional theory (DFT) method to investigate the mechanism and selectivity for the acetylene hydrogenation on the (111) surface of NiGa (n = 1, 3) IMCs, with a comparative study on the pristine Ni(111) surface. The results indicate that the adsorption energy of acetylene increased along with the Ni/Ga ratio, therefore a feasible acetylene adsorption on the Ga-rich surface guaranteed a low effective barrier, leading to the best activity for the NiGa(111) surface among three surfaces.