Fluorescent non-toxic bait as a new method for black rat (Rattus rattus) monitoring

The detection of synathropic rodents may be difficult since they are animals with nocturnal activity. Methods of their detection and monitoring rely mostly on indirect signs of their activity such as the presence of faeces, urine, consumed foods and damaged materials. Our experimental hypothesis was that the production of fluorescent faeces - following consumption of fluorescent bait - may be used for rodent monitoring. For this purpose we studied the production of fluorescent faeces, temporal dynamics and detectability in wild black rat (Rattus rattus). Wild black rats were individually housed in experimental cages with the wire-mesh grid floor and faeces were collected in short-time intervals. The peak of fluorescent activity in faeces was detected 10-20 hours after bait ingestion. We found that there is only relatively short delay between bait consumption and defecation and fluorescent faeces are easily detectable at distance using an ultraviolet hand lamp. Thus, this method can contribute to effective monitoring of rodent pests.Keywords: Rattus rattus, Fluorescent bait, Monitoring, Rodent contro

Synthesis of ‘unfeasible’ zeolites

Zeolites are porous aluminosilicate materials that have found applications in many different technologies. However, although simulations suggest that there are millions of possible zeolite topologies, only a little over 200 zeolite frameworks of all compositions are currently known, of which about 50 are pure silica materials. This is known as the zeolite conundrum—why have so few of all the possible structures been made? Several criteria have been formulated to explain why most zeolites are unfeasible synthesis targets. Here we demonstrate the synthesis of two such unfeasible’ zeolites, IPC-9 and IPC-10, through the assembly–disassembly–organization–reassembly mechanism. These new high-silica zeolites have rare characteristics, such as windows that comprise odd-membered rings. Their synthesis opens up the possibility of preparing other zeolites that have not been accessible by traditional solvothermal synthetic methods. We envisage that these findings may lead to a step change in the number and types of zeolites available for future applications

Structural analysis of IPC zeolites and related materials using positron annihilation spectroscopy and high-resolution argon adsorption

ETH authors thanks for the grant ETH 33 15-1. PE and JČ acknowledge the financial support from the Czech Science Foundation (P106/12/0189). JPR and JČ gratefully acknowledge the financial support from the European Union Seventh Framework Programme (FP7/ 2007-2013) under grant agreement no. 604307. HRTEM characterization was performed at the Advanced Microscopy Laboratory (LMA) and the research leading to these results has received funding from the European Union Seventh Framework Programme under Grant Agreement 312483 – ESTEEM2 (Integrated Infrastructure Initiative-I3).The advanced investigation of pore networks in isoreticular zeolites and mesoporous materials related to the IPC family was performed using high-resolution argon adsorption experiments coupled with the development of a state-of-the-art non-local density functional theory approach. The optimization of a kernel for model sorption isotherms for materials possessing the same layer structure, differing only in the interlayer connectivity (e.g. oxygen bridges, single- or double-four-ring building units, mesoscale pillars etc.) revealed remarkable differences in their porous systems. Using high-resolution adsorption data, the bimodal pore size distribution consistent with crystallographic data for IPC-6, IPC-7 and UTL samples is shown for the first time. A dynamic assessment by positron annihilation lifetime spectroscopy (PALS) provided complementary insights, simply distinguishing the enhanced accessibility of the pore network in samples incorporating mesoscale pillars and revealing the presence of a certain fraction of micropores undetected by gas sorption. Nonetheless, subtle differences in the pore size could not be discriminated based on the widely-applied Tao-Eldrup model. The combination of both methods can be useful for the advanced characterization of microporous, mesoporous and hierarchical materials.PostprintPeer reviewe

Synthesis of ‘unfeasible’ zeolites

R.E.M. thanks the Royal Society and the E.P.S.R.C. (Grants EP/L014475/1, EP/K025112/1 and EP/K005499/1) for funding work in this area. J.Č. and P.N. acknowledge the Czech Science Foundation for the project of the Centre of Excellence (P106/12/G015) and the European Union Seventh Framework Programme (FP7/ 2007-­‐2013) under grant agreement n°604307. The research leading to these results has received funding from the European Union Seventh Framework Programme under Grant Agreement 312483 – ESTEEM2 (Integrated Infrastructure Initiative–I3). We thank Professor Wuzong Zhou and Dr. Fengjiao Yu for their expertise in TEM and Daniel Dawson for help with NMR.Zeolites are porous aluminosilicate materials that have found applications in many different technologies. However, although simulations suggest that there are millions of possible zeolite topologies, only a little over 200 zeolite frameworks of all compositions are currently known, of which about 50 are pure silica materials. This is known as the zeolite conundrum - why have only so few of all the possible structures been made? Several criteria have been formulated to explain why most zeolites are unfeasible synthesis targets. Here we demonstrate the synthesis of two such 'unfeasible' zeolites, IPC-9 and IPC-10, through the assembly-disassembly-organization-reassembly mechanism. These new high-silica zeolites have rare characteristics, such as windows that comprise odd-membered rings. Their synthesis opens up the possibility of preparing other zeolites that have not been accessible by traditional solvothermal synthetic methods. We envisage that these findings may lead to a step change in the number and types of zeolites available for future applications.PostprintPeer reviewe

Impact of pore topology and crystal thickness of nanosponge zeolites on the hydroconversion of ethylbenzene

The gas-phase hydroconversion of ethylbenzene was investigated in the presence of intimate mixtures of ∗MRE, MFI and MTW-type zeolite nanosponges and a hydrogenating component (Pt/Al2O3). The nanomorphic zeolites were prepared using multiammonium surfactants acting as dual-porogenic agents directing the formation of micro- and mesopores simultaneously. The effects of the zeolite topology (pore size and dimensionality) and crystal thickness on the product selectivity of ultra-thin zeolite frameworks (<10 nm) were investigated. The enhanced catalytic activity confirmed the importance of improved molecular diffusion. These nanosponges were unique in producing more xylenes, suggesting lower confinement effects. The selectivity for p-xylene and the selectivity towards ethylbenzene hydroisomerization, dealkylation, disproportionation, transalkylation and hydrocracking were evaluated. Despite the similar <10 nm crystal thickness of all the nanosponge zeolites, the presence of spacious channel interconnections in MFI was concluded to remarkably impact the product selectivity compared to straight channels as in ∗MRE and MTW. Our findings clarify the relatively unexplored transformation of alkyl-aromatics over ultra-thin zeolite crystals, through five typical catalytic reactions of major industrial interest. © The Royal Society of Chemistry 20161321sciescopu

Mesoporous EU-1 zeolite as a highly active catalyst for ethylbenzene hydroisomerization

The hydroisomerization of ethylbenzene is an important industrial reaction to maximize the production of xylenes, and in particular, para-xylene. Zeolite EU-1 (with EUO topology) is commercially utilized in a physical mixture with a metallic phase (Pt/Al2O3). Herein, we have developed a micro-mesoporous EUO zeolite with a significant volume of intercrystalline mesoporosity to improve its catalytic performance in the industrial hydroisomerization of ethylbenzene. The use of a multivalent cationic surfactant as a capping agent was ideal to prevent uniform crystal growth and their aggregation, and to ensure the potential industrial applicability of the strategy. The corresponding mesoporosity and textural properties of nanosponge-like EUO were tuned according to the amount of the capping agent. The catalytic performance reflected the remarkable impact of a large exposed surface area (up to 55%) and a high amount of easily accessible Brønsted acid sites (up to 29%) in the EU-1 nanosponge on the catalytic yield. Our best catalyst revealed a three-fold increase in the conversion of ethylbenzene with no detrimental effects on the attained hydroisomerization yield. This approach presents a potential industrial capability in a wide range of catalytic applications as evidenced here in the hydroisomerization of ethylbenzene

Impact of pore topology and crystal thickness of nanosponge zeolites on the hydroconversion of ethylbenzene

The gas-phase hydroconversion of ethylbenzene was investigated in the presence of intimate mixtures of *MRE, MFI and MTW-type zeolite nanosponges and a hydrogenating component (Pt/Al2O3). The nanomorphic zeolites were prepared using multiammonium surfactants acting as dual-porogenic agents directing the formation of micro-and mesopores simultaneously. The effects of the zeolite topology (pore size and dimensionality) and crystal thickness on the product selectivity of ultra-thin zeolite frameworks

Mesoporous EU-1 zeolite as a highly active catalyst for ethylbenzene hydroisomerization

The hydroisomerization of ethylbenzene is an important industrial reaction to maximize the production of xylenes, and in particular, para-xylene. Zeolite EU-1 (with EUO topology) is commercially utilized in a physical mixture with a metallic phase (Pt/Al2O3). Herein, we have developed a micro-mesoporous EUO zeolite with a significant volume of intercrystalline mesoporosity to improve its catalytic performance in the industrial hydroisomerization of ethylbenzene. The use of a multivalent cationic surfactant as a capping agent was ideal to prevent uniform crystal growth and their aggregation, and to ensure the potential industrial applicability of the strategy. The corresponding mesoporosity and textural properties of nanosponge-like EUO were tuned according to the amount of the capping agent. The catalytic performance reflected the remarkable impact of a large exposed surface area (up to 55%) and a high amount of easily accessible Bronsted acid sites (up to 29%) in the EU-1 nanosponge on the catalytic yield. Our best catalyst revealed a three-fold increase in the conversion of ethylbenzene with no detrimental effects on the attained hydroisomerization yield. This approach presents a potential industrial capability in a wide range of catalytic applications as evidenced here in the hydroisomerization of ethylbenzene

Impact of pore topology and crystal thickness of nanosponge zeolites on the hydroconversion of ethylbenzene

The gas-phase hydroconversion of ethylbenzene was investigated in the presence of intimate mixtures of *MRE, MFI and MTW-type zeolite nanosponges and a hydrogenating component (Pt/Al2O3). The nano-morphic zeolites were prepared using multiammonium surfactants acting as dual-porogenic agents directing the formation of micro- and mesopores simultaneously. The effects of the zeolite topology (pore size and dimensionality) and crystal thickness on the product selectivity of ultra-thin zeolite frameworks (<10 nm) were investigated. The enhanced catalytic activity confirmed the importance of improved molecular diffusion. These nanosponges were unique in producing more xylenes, suggesting lower confinement effects. The selectivity for p-xylene and the selectivity towards ethylbenzene hydroisomerization, dealkylation, disproportionation, transalkylation and hydrocracking were evaluated. Despite the similar <10 nm crystal thickness of all the nanosponge zeolites, the presence of spacious channel interconnections in MFI was concluded to remarkably impact the product selectivity compared to straight channels as in *MRE and MTW. Our findings clarify the relatively unexplored transformation of alkyl-aromatics over ultra-thin zeolite crystals, through five typical catalytic reactions of major industrial interest