A balance between the catalytic activity and product selectivity remains a dilemma for the partial oxidation processes because the products are prone to be over-oxidized. In this work we report on the partial oxidation of benzyl alcohol using a modified catalyst consisting of nanosized Au-Pd particles (NP) with tin oxide (SnO x ) deposited on mesoporous silica support. We found that the SnO x promotes the autogenous reduction of PdO to active Pd 0 species on the Au-Pd NP catalyst (SnO x @AP-ox) before H 2 reduction, which is due to the high oxophilicity of Sn. The presence of active Pd 0 species and the enhancement of oxygen transfer by SnO x led to a high catalytic activity. The benzaldehyde selectivity was enhanced with the increase of SnO x content on catalyst SnO x @AP-ox, which is ascribed to the modulated affinity of reactants and products on the catalyst surface through the redox switching of Sn species. After H 2 reduction, the SnO x was partially reduced and Au-Pd-Sn alloy was formed. The formation of Au-Pd-Sn alloy weakened both the catalytic synergy of Au-Pd alloy NPs and the adsorption of benzyl alcohol on the reduced catalyst, thus leading to a low catalytic activity.

Perovskite-type LaCoO3 catalysts were studied for cyclohexane oxidation with molecular oxygen in a solvent-free system. Catalysts with various Lanthanum to Cobalt molar ratios were prepared through a modified citric acid procedure and characterized by different techniques. Among all catalysts, the best cyclohexane conversion results (8.3%) with a K/A oil (cyclohexanone and cyclohexanol) selectivity of 90% were obtained over LaCoO3 with a La to Co molar ratio of 1:1. The high catalytic activity on the perovskite-type LaCoO3 catalyst was explored by experimental and theoretical methods. Density functional theory-based calculations clarified the role of La and Co ions in oxygen and cyclohexane adsorption, respectively. The characterization results indicated that a single-phase LaCoO3 perovskite with a dominance of surface Co 3+ species and relatively high concentration of adsorbed oxygen species on the catalyst surface enhances the catalytic performance. This study presents insights into the design of a highly active, cost-effective, and green catalyst for cyclohexane partial oxidation.

Coffea canephora has high but inadequately exploited genetic diversity. This diversity, if well exploited, can sustain coffee productivity amidst climate change effects. Drought and heat stress are major global threats to coffee productivity, quality, and tradable volumes. It is not well understood if there is a selectable variation for drought stress tolerance in Robusta coffee half-sibs as a result of watering deficit pre-exposure at the germination stage. Half-sib seeds from selected commercial clones (KR5, KR6, KR7) and a pipeline clone X1 were primed with deficit watering at two growth stages followed by recovery and later evaluated for tolerance to watering deficit stress in three different temperature environments by estimation of plant growth and wilt parameters. Overall, the KR7 family performed the best in terms of the number of individuals excelling for tolerance to deficit watering. In order of decreasing tolerance, the 10 most promising individuals for drought and heat tolerance were identified as: 14.KR7.2, 25.X1.1, 35.KR5.5, 36.KR5.6, 41.KR7.5, 46.KR6.4, 47.KR6.5, 291.X1.3, 318.X1.3, and 15.KR7.3. This is the first prospect into the potential of C. canephora half-sibs’ diversity as an unbound source of genetic variation for abiotic stress tolerance breeding.

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Cowpea (Vigna unguiculata (L.) walp) is a legume crop mainly grown on small scale in low–input farming systems in Uganda. Cowpea bacterial blight (CoBB) disease caused by Xanthomonas axonopodis pv. vignicola (Burkh.) Dye is increasingly becoming a major hindrance to cowpea productivity. Sixty-four cowpea genotypes were evaluated for their response to bacterial blight disease (CoBB). Field experiments were carried out during the first and second rainy seasons using alpha lattice design with three replications. Data on disease incidence and severity, grain yield, days to 50% flowering, number of seeds per pod, pod length, number of peduncles per plant, and number of branches per plant were collected. Disease severity and incidence data was used to determine relative Area Under Disease Progress Curve (rAUDPC). Results showed significant differences (P ≤ 0.001) among the genotypes for rAUDPC in each season. The rAUDPC across the seasons indicated that genotypes NE 32, WC 32A, WC 26 and NE 44 with rAUDPC values ranging from 0.22 to 0.26 were resistant to CoBB whereas genotypes NE 31 and NE 40 with rAUDPC values 0.44 and 0.46 respectively were susceptible. The rAUDPC did not show any significant correlation with days to 50% flowering, yield and its components. This study suggested that the genotypes NE 32, WC 32A, NE 44, and WC 26 be used as prospective parents in breeding initiatives to develop bacterial blight-resistant varieties due to their high yields and resistance to CoBB.