**Abstract**

Metal nanoparticles (MNPs) are the main agents in heterogeneous catalysis. Hence, utilizing the effective physico-chemical methods to engage them to achieve the highest catalysts performance with well-controlled size, shape, and surface properties seems to be essential. The encapsulation of metal nanoparticles is a promising approach that enhances the catalytic activity of the materials. Not only the encapsulating structures can adjust the catalytic properties of metal nanoparticles, particularly selectivity, but also prevents them from agglomeration and sintering. In this chapter, the various encapsulating structures consist of yolk/core-shell and mesoporous structures, and encapsulating materials that are divided into three parts, including inorganic materials, metal–organic frameworks, and organic materials are presented.

**Keywords:** encapsulation, yolk/core-shell, mesoporous structures, catalyst, metal nanoparticles


*2.5. Experimental Protocol*

A recovery period of >72 h was required after the familiarization trial and between each testing day for all participants. On average, the time between trials was 192 ± 168 h. As sleep may have influenced exercise performance we asked participants to self-report their sleep duration prior to each visit. Participants then returned to the laboratory the following morning in a fasted, but well-hydrated, state between 05:30 and 08:30 a.m. Upon arrival, participants were asked to provide a urine sample to measure urine specific gravity using a hand-held refractometer to confirm hydration status [8]. Participants were provided with 250 mL of water to consume at their leisure before exercise and an additional 250 mL of water if their urine specific gravity indicated dehydration (>1.020). Thereafter, baseline measurements for height, weight, body composition, resting HR, satiety, GID, resting energy expenditure (REE), and capillary blood glucose (BG) were collected. GID and satiety were measured via a 100-mm visual analog scale (VAS) during baseline and one-minute post 5-km TT for each of the three experimental trials [31–33]. Each VAS scale was marked with "0 mm" (no GID; extreme hunger) and "100 mm" (extreme GID; extremely full) and participants were asked to draw a vertical line indicating their perceived GID and satiety accordingly. Both VAS and categorical scale have been documented in the literature as reliable perceptual measures of pain or discomfort [31–33].

REE was collected while participants rested quietly in a seated position with the headpiece and mask on for 15 min in a climate-controlled room with the metabolic cart system described above. Respiratory exchange ratio (RER) was recorded and relative substrate utilization (%FAT and %CHO) was estimated [34]. The last ten minutes were used for data analysis. Resting HR was then measured followed by blood sampling via finger stick. Capillary BG concentrations were measured using a commercially available glucometer (OneTouch Ultra 2 LifeScan, Milpitas, CA, USA) [35].

#### *2.6. Incremental Exercise Test and 5-km Time Trial*

Fifteen minutes following completion of baseline measurements, participants completed a three-minute warm up at a self-selected pace on the treadmill. Following the warm up, participants completed an incremental exercise test (IET) comprising of three stages of three minutes each at exercise intensities of 55, 65, and 75% of VO2peak [34]. HR, RPE, and GID were recorded during the last 15 s of each three minute each stage. GID and RPE were measured during exercise using a categorical scale [31–33]. Upon completion of the IET, participants were given a five-minute active rest period where they were instructed to walk on the treadmill at a comfortable pace to allow their HR to return closer to baseline. Participants were allowed to use the restroom quickly as long as a researcher monitored them for safety. Following the active rest period, participants completed a 5-km TT. The TT was conducted rather than time-to-exhaustion to better mimic competition and pacing demands [36] and due to greater reliability in the repeatability of the results [37]. Participants were instructed to treat each TT as a competitive event and accordingly provide maximal effort. Participants could only see their distance during the TT and the time and speed were blinded. Additionally, participants ran both the IET and 5-km TT at 1% grade to best simulate the oxygen cost of outdoor running [38]. HR, RPE, and GID measurements were taken every 1 km. BG and HR were measured immediately post exercise and 10 min post exercise. HR, GID (VAS), and satiety (VAS) were also recorded one minute post 5-km TT.


*2.3. Adhesion of Coatings*

The scratch and wear resistance of the coatings were assessed using a Teer ST3001 scratch–wear tester (Teer Coatings Ltd, Droitwich, UK) [27]. The coated surfaces were evaluated using a Rockwell diamond tip (radius 200 ȝm). A load rate of 100 N·miní1 and a constant sliding speed of 10.0 mm·miní1 were used with the load increasing from 10 to 40 N. The scratch tracks were examined using a Cambridge Stereoscan 200 scanning electron microscope (Cambridge Instruments, Cambridge, UK) in order to detect any flaking.


**5.6 Isolation and purification**

Microorganisms of 3 samples have been isolated and then purified. Specifically:

PCA has been utilized as sterile agar culture medium. Isolation has been accomplished through suspension dilutions (up to 109 ) of samples and plating by inclusion of 1 ml for each dilution. After incubation for 24 hours at 27°C, largest colonies have been purified by smear on PCA plating. Purified strains have been stored at

**Table 5.** *PCA agar– liter1*

20°C in PCB at 20% glycerol and at 4°C in slant test tubes, to be collected for the subsequent identification tests. On the same dishes, for sludges and wastewater, prior to smear purification, a bacterium count of colonies of dilutions showing the greatest growth has been made and the results have been expressed in CFU/ml.